Engineering material reference

High-carbon chromium bearing steel. The most widely used bearing steel worldwide. Extremely high hardness and wear resistance after heat treatment. Standard for ball and roller bearings, precision shafts, and measuring instruments.

Through-hardening bearing steel with higher Mn than 100Cr6 for improved hardenability in larger cross-sections. Used for bearing rings, rolling elements, and precision components where 100Cr6 cannot achieve sufficient core hardness due to section size.

Low-carbon Cr-Mo steel for elevated temperature pressure equipment. Excellent creep resistance up to 530°C. The standard grade for boiler tubes, headers, and pressure vessels in power generation and petrochemical industries.

Sulfur-manganese free-cutting steel, not intended for heat treatment. Excellent machinability (significantly better than standard carbon steels). Used for high-volume CNC-machined parts: bolts, nuts, pipe joints, bushings, fittings, and other turned components.

Leaded free-cutting steel — the highest machinability rating among carbon steels. Pb+S combination gives excellent chip breaking and surface finish. The standard grade for high-volume automatic lathe parts. Used for screws, nuts, bolts, bushings, pins, and automotive turned parts. ≈ AISI 12L14.

Low-alloy Cr-Mo steel for elevated-temperature service. Good creep resistance up to 500°C. The standard grade for boiler tubes, headers, superheater tubes, and pressure equipment in power generation. Lower alloy content than 10CrMo9-10.

High-Ni case hardening steel — Ni 3.0-3.5%, Cr 0.6-0.9%, no Mo. Ni gives excellent core toughness at low temperature — used for case-hardened parts operating in cold environments. THE classic aerospace/defense case-hardening steel (BS S130/S131). Used for aircraft gears, military vehicle transmission gears, and cryogenic case-hardened components.

Martensitic precipitation-hardening stainless steel. Similar to 17-4PH but with better transverse ductility and toughness due to lower delta ferrite. Used for aerospace structural components, nuclear reactor parts, food processing equipment, and high-performance fasteners.

Low-carbon chromium-molybdenum creep-resistant steel for elevated temperature service up to ~550°C. Good weldability (low C) combined with long-term creep strength. Used for pressure vessel shells, boiler drums, superheater tubes, and petrochemical reactors. Part of the Cr-Mo series alongside 13CrMo4-5 and 10CrMo9-10.

Cr-Mo-V steel for elevated temperature fastener applications. Retains strength up to 540°C. Used for high-temperature bolts, studs, and nuts in power plants, steam turbines, and pressure vessel flanges. Specified in EN 10269 for creep-resistant fasteners.

Heavy-duty NiCrMo case hardening steel — Ni 3.0-3.5% for maximum core toughness and deep hardenability. For the largest case-hardened parts: heavy truck ring gears, mill pinions, crane slewing gears, and large marine gearboxes up to 500mm ruling section. Surface HRC 60-63 with extremely tough core. More Ni than 17CrNiMo6 = even deeper hardenability.

Low-carbon case-hardening steel with manganese and chromium. Excellent for carburizing to produce a hard, wear-resistant surface with a tough core. Standard choice for gears, camshafts, piston pins, and transmission components.

Free-cutting variant of 16MnCr5 (1.7131) — sulfur addition (0.020-0.040%) for improved machinability on CNC automatics. Same case-hardening properties: surface 60-62 HRC after carburizing. THE high-volume automotive gear steel where machining cost matters. Used for transmission gears, shafts, pinions, and other carburized parts produced on CNC lathes and multi-spindle automatics.

Nickel-chromium case hardening steel — Ni 0.8-1.1%, Cr 0.6-1.0%, no Mo. Between 16MnCr5 (Mn-Cr) and 14NiCr14 (high-Ni) in hardenability. Better core toughness than 16MnCr5 due to Ni. Used for heavy-duty sprockets, pinions, worms, pins, and shafts requiring case-hardened surface (HRC 58-62) with tough core. EN 10084 standard.

The most widely used precipitation-hardening stainless steel. Combines high strength (up to 1310 MPa UTS) with corrosion resistance comparable to 304. Delivered solution-annealed and hardened by simple low-temperature aging. Used in aerospace, medical, oil & gas, and nuclear applications.

Chrome case-hardening steel — the simplest Cr-alloyed carburizing grade in EN 10084. 0.7-1.0% Cr gives better hardenability and wear resistance than unalloyed C20 but less than 16MnCr5. Used for smaller gears, camshafts, spindles, pins, and bushings with medium wear requirements. ≈ SAE 5117.

Premium CrNiMo case hardening steel for demanding gear applications. Ni 1.2-1.5% + Mo 0.25-0.35% give excellent core toughness and deep hardenability — suitable for large gears up to 400mm ruling section. Surface HRC 60-63 after carburizing. THE wind turbine gearbox steel. Also used for large industrial gearboxes, mining equipment, and heavy truck transmissions.

Premium Cr-Ni-Mo case-hardening steel for the most demanding gear applications. Excellent core toughness and hardenability for large cross-sections. The standard gear steel for wind turbines, heavy-duty gearboxes, and aerospace gearing.

Low-carbon manganese-boron steel for case hardening or through-hardening. Boron (0.0008-0.005%) provides cost-effective hardenability without expensive Cr/Mo/Ni. Lower C than 22MnB5 — better weldability and formability before hardening. Used for chains, fasteners, agricultural implements, and structural parts that are induction-hardened or carburized.

Manganese-chromium case-hardening steel with higher core strength than 16MnCr5. Used for heavily loaded gears, shafts, camshafts, and transmission components requiring high surface hardness with tough core. Popular in automotive and heavy machinery.

Free-cutting variant of 20MnCr5 with controlled sulfur (0.020-0.040%). Improved machinability for high-volume gear production without significant loss of mechanical properties. The standard free-cutting case-hardening steel in European automotive gear manufacturing.

Vanadium-microalloyed Mn steel — V 0.08-0.15% for grain refinement and precipitation strengthening. Can be used in as-forged (controlled-cooled) condition without separate Q&T. Lower cost than CrMo grades for moderate-strength applications. Used for hydraulic cylinders, shafts, and structural forgings where UTS 700-850 MPa is sufficient.

Free-cutting variant of 20NiCrMo2-2 (1.6523/AISI 8620) — S addition for improved machinability on CNC automatics. Same case-hardening properties as 8620. THE free-cutting automotive gear and pinion steel for high-volume CNC production. Surface HRC 58-62 after carburizing with good core toughness.

Free-cutting variant of 20NiCrMo6-4 — S addition for improved machinability. NiCrMo case hardening steel with excellent core toughness and deep hardenability. Used for high-volume CNC production of automotive transmission gears, pinions, and shafts.

Cr-Mo-V high-temperature alloy steel for bolting at elevated temperatures up to ~550°C. Higher Cr and Mo than 15CrMoV5-9 for improved creep resistance. Used for turbine casing bolts, main flange bolts in steam power plants, and high-pressure/high-temperature petrochemical fasteners.

THE press hardening (hot stamping) boron steel — used in virtually every modern car for B-pillars, bumper beams, and side impact reinforcements. As-delivered: ferritic-pearlitic, UTS 450-750 MPa, formable. After hot stamping + die quenching: fully martensitic, UTS 1300-1650 MPa. Boron (0.002-0.005%) provides critical hardenability at low cost. Usually AlSi or Zn coated to prevent oxidation during austenitizing at 880-950°C.

Manganese-chromium case hardening steel with Mn+Cr for good hardenability. Part of the 20MnCr5 family (EN 10084). Surface hardness 60-62 HRC after carburizing + hardening. Good core toughness. Used for transmission gears, pinions, camshafts, piston pins, and small-to-medium sized carburized components.

Cold-heading boron steel — optimized for cold forming of high-strength fasteners. Boron gives hardenability equivalent to much more expensive Cr-Mo alloys. Supplied spheroidized for cold heading, then quenched+tempered after forming. Property class 10.9 bolts are commonly made from this grade. Used for high-strength bolts (M8-M24), screws, studs, and threaded fasteners for automotive and construction.

CrMoV nitriding and warm-work steel — Cr 1.2-1.5%, Mo 0.45-0.65%, V 0.25-0.35%. Lower Cr than 30CrMoV9 (2.3-2.7%) but higher Mo — better creep resistance at elevated temperature. Used for warm-work tools (forging dies to 400°C), nitrided piston rings, and power generation components. Also specified in EN 10269 for fasteners at elevated temperature.

Super-austenitic stainless steel with 6% Mo. PREN >40 for outstanding pitting and crevice corrosion resistance. Bridges the gap between standard austenitics and nickel alloys. Used in seawater systems, flue gas desulfurization, bleach plants, and offshore.

Medium-carbon chromium-molybdenum steel with good toughness and weldability. Used for seamless tubes, pressure vessels, aircraft structural parts, and automotive components. Better weldability than 42CrMo4 due to lower carbon.

Free-cutting variant of 25CrMo4 (1.7218) — sulfur addition (0.020-0.040%) for improved chip formation on CNC automatics. Same mechanical properties after Q&T. THE high-volume CrMo steel for CNC-machined automotive parts where cycle time matters. Used for transmission shafts, steering components, bolts, and any 25CrMo4 application produced on automatic lathes.

Cr-Mo-V high-temperature bolt steel for service up to ~540°C. Used alongside 21CrMoV5-7 in power plant bolting — slightly higher Cr+Mo for improved creep resistance at the cost of toughness. Used for turbine casing bolts, high-pressure steam valve studs, and boiler fasteners.

CrNiMo quenched & tempered steel — low-C (0.22-0.29%) variant in the NiCrMo QT family. Better weldability than 34CrNiMo6 due to lower C. Good combination of strength (UTS 800-1000 MPa) and toughness for bolts, anchor bolts, studs, and structural fasteners in offshore and bridge construction.

Low-carbon Cr-Mo QT steel — between 25CrMo4 and 30CrMo4. Excellent weldability for a QT grade (low C). Good hardenability for medium sections. Primary use: high-pressure gas cylinders (EN ISO 9809-1). Also used for pressure vessels, boiler parts, and automotive components where weldability + moderate strength are needed.

Manganese-chromium-boron steel for direct hardening and hot stamping. Boron addition (0.0008-0.005%) dramatically improves hardenability at low cost. The standard grade for automotive press-hardened body-in-white components (B-pillar, side impact beams, bumper reinforcements).

Chromium quenched & tempered steel — 1% Cr, no Mo. The economy QT alloy steel: Cr improves hardenability over plain carbon steels at lower cost than CrMo grades (25CrMo4, 42CrMo4). Adequate for moderately loaded parts up to ~40mm ruling section. Used for bolts, studs, shafts, axles, and general machine parts where better hardenability than C-steel is needed but CrMo cost is not justified.

Manganese case-hardening steel for large components requiring deep case depth. Higher Mn than 16MnCr5 for better hardenability in thick sections. Used for large gears, heavy-duty pinions, and mining/construction equipment.

Austenitic stainless steel with the highest work-hardening rate of all 300-series grades. Lower Cr and Ni (17/7 vs 18/9 for 304) makes it metastable — cold working induces martensite transformation for extreme strength (UTS >1300 MPa in full-hard temper). THE stainless spring steel. Used for stainless springs, washers, clips, structural components requiring high strength + corrosion resistance, and railway car bodies.

Higher-carbon variant of 304 (C max 0.15% vs 0.08%). The original "18-8" stainless steel. Higher C gives better strength after cold work but makes it susceptible to intergranular corrosion after welding. Largely superseded by 304/304L but still specified for springs and high-strength cold-worked applications. Used for springs, screen cloth, architectural trim, and wire forms.

Free-machining austenitic stainless steel — the most machinable of all austenitic grades. 0.15-0.35% S (as MnS inclusions) provides excellent chip-breaking. Trade-off: lower corrosion resistance than 304, poor weldability (hot cracking risk), and not suitable for cold forming. Used for high-volume automatic lathe parts: fittings, valves, screws, shafts, and precision components.

The world's most widely used stainless steel — the original 18/8 austenitic. Good corrosion resistance in atmospheric, organic, and inorganic environments. Excellent formability and weldability. Not recommended for chloride-rich or marine environments (use 316L). Used in food processing, kitchen equipment, architecture, tanks, and general engineering.

The most widely used austenitic stainless steel. Excellent corrosion resistance, good formability and weldability. Standard choice for food processing, chemical, and architectural applications.

Low-carbon version of 304. Maximum 0.030% C prevents sensitization during welding — no post-weld heat treatment needed. The standard choice for welded structures in food, chemical, and pharmaceutical industries. Often dual-certified with 1.4301.

Nitrogen-enhanced low-carbon 304. The N addition (0.12-0.22%) increases yield strength ~40% over 304L without reducing corrosion resistance or weldability. Used for pressure vessels, storage tanks, and cryogenic applications where higher design stress is needed.

High-chromium austenitic stainless for high-temperature service. Better oxidation resistance than 304 due to higher Cr (22-24%) and Ni (12-14%). Maximum service temperature ~1000°C (intermittent). Used for furnace parts, heat exchangers, fluidized bed combustors, kiln liners, and boiler baffles.

Low-to-medium carbon Cr-Mo QT steel — lower C than 34CrMo4/42CrMo4 giving better weldability and toughness. THE gas cylinder and pressure vessel grade in Europe (EN ISO 9809). Good hardenability for medium sections. Also used for automotive crankshafts, gears, and high-pressure hydraulic components. AISI 4130 equivalent.

THE Cr-Mo-V nitriding steel — Cr 2.3-2.7% forms hard CrN nitrided case (800 HV surface). V addition for secondary hardening. Core QT to UTS 1080-1270 MPa before nitriding at 570-580°C. Used for piston rods, valve stems, cylinder liners, turbine parts, and any component needing extreme surface hardness + fatigue resistance without distortion (low nitriding temp).

High-strength quenched and tempered Cr-Ni-Mo steel for very large cross-sections. Even better hardenability than 34CrNiMo6 due to higher Cr and Ni content. Used for large shafts (>200mm diameter), heavy-duty gears, turbine rotors, and critical aerospace components.

High-chromium, high-nickel austenitic for the highest service temperatures among standard austenitics. Oxidation resistance to ~1100°C (continuous). Higher Cr/Ni than 309S. Used for furnace parts, radiant tubes, heat treatment baskets, kiln liners, and high-temperature flue gas equipment.

Standard-carbon austenitic stainless steel with molybdenum. Higher C than 316L (max 0.07% vs 0.03%) giving slightly higher strength. Same corrosion resistance as 316L. Used where welding is not required or post-weld solution annealing is possible.

Low-carbon austenitic stainless steel with molybdenum addition. Superior corrosion resistance to 304, especially against chlorides and pitting. Standard choice for chemical processing, marine, medical implants, and pharmaceutical equipment.

Nitrogen-enhanced low-carbon version of 316. The N addition (0.12-0.22%) increases yield strength by ~30% over 316L without losing corrosion resistance or weldability. Used for pressure vessels, nuclear components, and structural applications requiring higher design stress.

Titanium-stabilized austenitic stainless steel with molybdenum. Stabilization prevents sensitization during prolonged high-temperature exposure. Very popular in Germany for chemical, pharmaceutical, and food processing. Being replaced internationally by 316L (1.4404) for most applications.

Low-carbon austenitic with 3-4% Mo — higher Mo than 316L (2-3%). Better pitting and crevice corrosion resistance (PREN ~30 vs ~25). Used in aggressive chemical environments where 316L is borderline: pharmaceutical, dye production, and organic acid processing.

Deep nitriding steel with 3% Cr — the highest Cr content in the EN 10085 nitriding series. Produces the deepest and hardest nitrided case (surface hardness >900 HV, case depth >0.5mm). Core strength 800-1000 MPa QT. Used where maximum surface hardness and wear resistance with a tough core is needed: large gears, cylinder liners, spindles, precision measuring tools, and heavy-duty sliding components.

THE standard nitriding steel — Cr-Mo-V combination optimized for gas nitriding. Vanadium refines grain and forms hard VN nitrides (surface >750 HV). Better core toughness than 31CrMo12 at similar strength. THE default choice when "nitriding steel" is specified without further detail. Used for crankshafts, gears, spindles, extrusion screws, and precision machine components.

Heavy-duty NiCrMo quenched & tempered steel with high Ni (3.0-3.5%) — maximum hardenability in the QT range. UTS 1100-1300 MPa. Used for the most heavily loaded shafts, crankshafts, and structural components where 34CrNiMo6 hardenability is insufficient. Large cross-sections up to 250mm. Aerospace landing gear, heavy mining equipment, and large hydraulic press components.

Titanium-stabilized austenitic stainless steel. Similar to 304 but with Ti addition to prevent carbide precipitation during welding and high-temperature service (up to 800°C). Used for aircraft exhaust manifolds, boiler casings, jet engine parts, and chemical processing.

Premium CrMoV nitriding steel with highest Cr (3%) and Mo (1%) in the nitriding series — designed for maximum core strength after nitriding. Higher strength than 31CrMoV9 and 31CrMo12. AMS 6481 for aerospace. THE gun barrel material. Nitrided surface reaches 860+ HV while maintaining tough core at 415 HV. Used for gun barrels, high-performance gears, ball bearing races, crankshafts, and components requiring the ultimate combination of core strength + surface hardness.

Boron-alloyed case hardening steel with higher C (0.30-0.36%) than typical case-hardening grades. B addition for cost-effective hardenability. After carburizing: HRC 58-62 surface with tough core. THE chain link and chain pin steel — also used for agricultural equipment, earth-moving parts, and wear-resistant components requiring surface hardness with impact resistance.

Niobium-stabilized austenitic stainless steel. Nb forms NbC instead of CrC, preventing sensitization during welding or high-temp service (425-860°C). Alternative to 321 (Ti-stabilized). Used for welded structures in chemical processing, aircraft exhaust systems, and high-temp piping.

Medium-carbon chromium steel with moderate hardenability. Used for components requiring moderate through-hardening: axles, shafts, connecting rods, bolts, and general machine parts. Less expensive alternative to 41Cr4 for smaller cross-sections.

THE classic aluminum-containing nitriding steel — Al 0.8-1.2% forms extremely hard AlN nitrided layer (900-1100 HV surface). Cr 1.0-1.3% + Ni 0.85-1.15% provide core strength. Highest achievable surface hardness of all nitriding steels. Used for cylinder liners, piston rings, crankshafts, spindles, and gauges where maximum nitrided hardness is critical. Also known as 34CrAlNi7-10.

Medium-carbon Cr-Mo quench and temper steel. Lower C than 42CrMo4 for better weldability and toughness. Used for welded pressure vessels, seamless tubes for high-temperature service, bicycle frames, and moderately stressed machine components.

Free-cutting variant of 34CrMo4 (1.7220) — S 0.020-0.040% for improved machinability on CNC automatics. Same Q&T properties. Used for high-volume CNC production of shafts, connecting rods, bolts, and automotive drivetrain components where machining cycle time is critical.

High-strength quenched and tempered Cr-Ni-Mo steel. Excellent hardenability and toughness, suitable for large cross-sections. Used for heavy-duty shafts, gears, turbine parts, and aerospace components.

Free-cutting variant of 34Cr4 (1.7033) — sulfur addition (0.020-0.040%) for improved machinability on CNC automatics. Same QT properties as 34Cr4. Used for shafts, spindles, bolts, studs, and automotive components in high volume on automatic lathes.

Nickel-chromium-molybdenum QT steel with 1.2-1.6% Ni for good toughness and hardenability. Between 34CrNiMo6 and 39NiCrMo3 in the alloy series. Good balance of strength, toughness, and fatigue resistance. Used for large crankshafts, heavy gears, turbine shafts, and highly stressed bolts in energy and heavy machinery sectors.

Boron micro-alloyed QT steel — 0.0008-0.0050% B multiplies hardenability dramatically at minimal cost. Achieves similar through-hardening to 41Cr4 or 42CrMo4 at lower alloy cost. THE cost-optimized approach for automotive fasteners, bolts, and cold-forged QT parts. Used for high-strength bolts (class 10.9/12.9), tie rods, stabilizer bars, and any mass-produced QT part where total alloy cost per ton matters.

Chromium-molybdenum Q&T steel — between 25CrMo4 (lower C) and 42CrMo4 (higher C). Good balance of through-hardenability and toughness for medium-sized parts. Used for shafts, gears, bolts, studs, and structural components in oil/gas and power generation. Better weldability than 42CrMo4 due to lower C.

Cr-Ni-Mo quenching and tempering steel for medium-high strength applications. Good balance of strength and toughness. Used for automotive connecting rods, crankshafts, gears, high-strength bolts, and heavily loaded machine parts.

Ultra-high-strength nickel-chromium-molybdenum QT steel. 4% Ni gives exceptional deep hardenability — air-hardening up to 90mm, through-hardening up to 300mm. UTS 1100-1300 MPa QT with good toughness. White-spot sensitive — dehydrogenation after forging mandatory. French designation 35NCD16. Used for landing gear, aerospace structural parts, heavy-duty shafts, racing components, and mining/construction equipment.

Simple chromium QT steel without Mo — lower cost than CrMo grades. 1% Cr gives adequate hardenability for small-to-medium sections (up to ~40mm). Close to AISI 5135. Used for bolts, studs, axles, shafts, and general mechanical engineering where moderate strength suffices and Mo premium is not justified.

Boron press-hardening steel — higher C (0.36-0.42%) than 22MnB5 (0.20-0.25%) for higher final strength (UTS ~1800 MPa vs ~1500 for 22MnB5). Used for ultra-high-strength automotive structural parts where 22MnB5 is not strong enough: A/B-pillar reinforcements, bumper beams, door intrusion beams. Hot-stamped at 880-950°C then die-quenched to full martensite.

Microalloyed precipitation-hardened forging steel. Achieves high strength directly from forging heat — no separate quench & temper needed. Cost-effective alternative to QT steels for automotive crankshafts, connecting rods, and other high-volume forged components.

Silicon spring steel with lower C (0.35-0.42%) than 55Si7 — better toughness and fatigue life at the cost of slightly lower maximum hardness. Si (1.5-1.8%) gives excellent hot sag resistance to ~250°C. THE automotive engine valve spring material in many European OEMs. Also used for clutch springs, suspension springs, and applications requiring fatigue endurance under dynamic loading.

Nickel-chromium-molybdenum quench & temper steel. Similar to AISI 4340 but with lower Ni — more economical. Good hardenability for sections up to ~80mm. Excellent balance of strength, toughness, and fatigue resistance. High white-point sensitivity — hydrogen control required. Used for crankshafts, connecting rods, gear shafts, landing gear components, and heavy-duty machinery parts.

NiCrMo quenched & tempered steel — excellent combination of strength (UTS 1000-1200 MPa) and toughness. Ni 0.9-1.2% gives good low-temperature impact. Between 34CrNiMo6 (higher alloy) and 42CrMo4 (no Ni) in the performance/cost spectrum. Used for heavy-duty axles, crankshafts, large bolts, connecting rods, and hydraulic cylinder rods.

Lowest-chromium ferritic stainless steel with Ti stabilization. Developed specifically for automotive exhaust systems as a cost-effective alternative to austenitic grades. Good oxidation resistance to ~800°C. Used for exhaust manifolds, catalytic converters, mufflers, and heat shields.

Chromium Q&T steel with higher Cr (1.3-1.6%) than 41Cr4 (0.9-1.2%) — deeper hardenability for larger ruling sections. Used for heavy shafts, large bolts, and machine components up to ~60mm ruling section where 41Cr4 would not through-harden. Also offers slightly better wear resistance and corrosion resistance than lower-Cr grades.

Pre-hardened plastic mold steel — delivered at 28-32 HRC, ready for machining without further heat treatment. The European equivalent of AISI P20. Cr-Mn-Mo composition for good through-hardenability in large sections. THE workhorse mold base material for injection molds, compression molds, and die casting dies. Good machinability, polishability, and photo-etchability. Used for mold frames, large injection molds, blow molds, and structural die components.

Free-machining variant of 40CrMnMo7 (1.2311/P20) — sulfur addition (0.05-0.10%) for significantly improved machinability. Same pre-hardened delivery condition (28-32 HRC). 30-40% faster machining than 1.2311. Slight trade-off in polishability due to MnS inclusions. Used where machining cost matters more than mirror polish: large mold frames, structural mold components, and prototype molds.

High-strength Cr-Ni-Mo quench and temper steel. Higher C than 34CrNiMo6 for greater strength, with excellent hardenability from Ni+Mo combination. Used for heavy-duty crankshafts, connecting rods, high-strength bolts (class 12.9), gears, and critical structural components in large cross-sections.

High-nickel Cr-Mo quench & temper steel for large cross-sections. 1.6-2.0% Ni gives superior hardenability compared to 39NiCrMo3 — through-hardening up to ~130mm diameter. Close to AISI 4340 composition. Used for heavy crankshafts, large gears, turbine shafts, connecting rods, and critical structural fasteners in energy and heavy machinery sectors.

High-alloy NiCrMo Q&T steel — Ni ~2%, Cr ~1%, Mo ~0.5%. Very deep hardenability for large cross-sections. UTS 1100-1300 MPa. Used for heavy-duty crankshafts, landing gear, rock drill components, and large forgings requiring uniform through-hardening. Between 34CrNiMo6 and 36NiCrMo16 in hardenability.

The basic martensitic stainless steel — 12% chromium with moderate carbon. Hardenable by heat treatment to provide good strength with moderate corrosion resistance. Used for steam turbine blades, pump shafts, valve components, bolts, and mining equipment.

Medium-carbon chromium steel with good hardenability. Standard grade for induction-hardened and nitrided components. Used for crankshafts, gears, axle shafts, bolts, studs, and machine parts requiring surface hardening.

Chromium-molybdenum QT steel — very close to 42CrMo4 (1.7225) with slightly lower carbon. Essentially interchangeable with 42CrMo4 for most applications. Sometimes specified where marginally better weldability than 42CrMo4 is needed. Same applications: gears, shafts, crankshafts, bolts, hydraulic components.

Free-cutting variant of 41Cr4 (1.7035) — sulfur addition (0.020-0.040%) for improved chip formation on CNC automatics. Same mechanical properties as 41Cr4 after Q&T. UTS 900-1100 MPa. Used for high-volume automotive shafts, bolts, spindles, and connecting rods on automatic lathes. Most popular Cr-only QT steel for CNC mass production.

Medium-carbon martensitic stainless steel. Higher hardness than 410 but lower than 420C (1.4034). Good balance of strength, corrosion resistance and machinability. Used for turbine blades, pump shafts, valves, bolts, surgical instruments, and cutlery.

High-carbon martensitic stainless steel. Higher hardness than 410 (up to 56 HRC). The standard knife steel for European cutlery. Used for kitchen knives, pocket knives, surgical scalpels, machine blades, roller bearings, and valve components. Not weldable.

High-strength quenched and tempered chromium-molybdenum steel. Widely used for shafts, gears, crankshafts, connecting rods, and high-strength bolts. Excellent hardenability and good fatigue resistance.

Free-cutting variant of 42CrMo4 with controlled sulfur content (0.020-0.040%). Improved machinability while maintaining essentially the same mechanical properties. Used for high-volume CNC machined components: gears, shafts, bolts, and automotive parts.

Chromium-vanadium quenched & tempered steel — higher Cr (1.3-1.6%) than 41Cr4 plus V (0.10-0.20%) for grain refinement and secondary hardening. Good fatigue life and wear resistance. Used for heavily loaded shafts, gears, piston rods, and mining equipment where higher hardenability and finer grain than 41Cr4/42CrMo4 are needed.

Vanadium-microalloyed medium-carbon steel for controlled-cooling after forging — achieves target properties without separate Q&T heat treatment ("as-forged" concept). V precipitates (VN, VC) give precipitation strengthening during air cooling. THE modern automotive crankshaft steel — replaces 42CrMo4 Q&T at lower total cost (no heat treatment furnace needed). Also used for connecting rods and large forged parts.

Ferritic chromium stainless steel with good corrosion resistance and formability. Lower cost than austenitic grades. Used for automotive trim, kitchen sinks, architectural panels, and appliance components.

Nickel-bearing martensitic stainless steel with higher corrosion resistance than 410/420. Highest strength of the standard martensitic grades (up to 1100 MPa). Used for marine shafts, propeller shafts, high-strength fasteners, valves, and pump components.

17% Cr Ti-stabilized ferritic stainless. Cost-effective alternative to 304 for many applications — no Ni means ~30-40% lower cost. Immune to chloride SCC. Used for automotive exhaust systems (downstream), kitchen sinks, washing machine drums, heat exchangers, and architectural trim.

High-carbon martensitic stainless steel with molybdenum and vanadium. Hardenable to 58+ HRC while maintaining moderate corrosion resistance. Used for cutlery, surgical instruments, valve components, bearings, and pump parts where hardness and corrosion resistance are both needed.

Highest-hardness standard martensitic stainless steel. Achieves 57-60 HRC — the hardest commonly available stainless grade. Excellent wear resistance from chromium carbides. Used for bearings, races, valve components, surgical instruments, high-end cutlery, and precision molds.

Stabilized ferritic stainless steel with Mo addition. A cost-effective alternative to 316L for applications where austenitic properties are not needed. Excellent resistance to chloride stress corrosion cracking. Used for hot water tanks, solar collectors, automotive exhaust, and catering equipment.

Medium-carbon chromium steel for quenching and tempering. Good hardenability for medium cross-sections. Used for crankshafts, connecting rods, spindles, bolts, and other moderately stressed machine parts requiring through-hardening.

Higher-carbon CrMo Q&T steel — 0.42-0.50% C vs 0.38-0.45% for 42CrMo4. Higher maximum hardness (HRC 52-56 surface after induction) and tensile strength (UTS 1000-1200 MPa QT) at the expense of slightly reduced toughness and weldability. Used where 42CrMo4 is not quite hard/strong enough: heavy-duty gear shafts, large bolts (12.9 class), crankshafts, and torsion bars.

Silicon spring steel with high elastic limit. Standard flat/leaf spring steel in Europe. Si provides high sag resistance. Used for leaf springs, Belleville washers, lock washers, and agricultural machine springs.

High-carbon Cr-Mo steel for springs and high-strength applications. Higher carbon than 42CrMo4 for greater hardness and spring properties. Used for coil springs, leaf springs, torsion bars, highly stressed bolts, and heavy-duty shafts.

Chromium-vanadium spring/tool steel — identical alloy system to 51CrV4 (1.8159) but recognized as a separate grade in some standards. Dual use: heavy-duty springs (EN 10089) AND cold work tools (knives, shear blades). V improves temper resistance and grain refinement. UTS 1200-1500 QT. Used for heavy leaf springs, stabilizer bars, torsion bars, and cold work cutting tools.

CrMoV alloyed spring steel — THE European automotive suspension spring material. CrMo gives deep hardenability for large coil springs, V adds grain refinement and secondary hardening for fatigue resistance. UTS 1350-1600 MPa QT. Used for hot-formed coil springs (cars, trucks), leaf springs, torsion bars, and stabilizer bars. Excellent sag resistance to 200°C.

Chromium-vanadium spring steel. The most important European spring steel grade. Excellent fatigue resistance and high elastic limit after heat treatment. Used for coil springs, leaf springs, torsion bars, anti-roll bars, and high-strength fasteners.

Si-Cr spring steel for high-performance automotive suspension and valve springs. Lower sag tendency than 46Si7 due to Cr addition. The standard European valve spring steel. Used for suspension springs, valve springs, torsion bars, and stabilizer bars where fatigue resistance is critical.

Chromium spring steel — simpler and cheaper than 51CrV4 (no vanadium). 0.75% Cr provides adequate hardenability for flat and small-diameter round springs. Used for leaf springs, agricultural springs, lock springs, and general-purpose springs where the V-premium of 51CrV4 is not justified.

Silicon spring steel — Si (1.5-2.0%) provides high elastic limit and excellent fatigue resistance without expensive Cr/V additions. Better heat resistance than Cr-spring steels — retains spring properties to ~250°C. Used for valve springs, clutch springs, hot-wound coil springs, and applications with moderate elevated temperature exposure. Cheaper than CrV spring steels.

Heavy-duty hot work tool steel with high Ni (1.5-1.8%) for exceptional toughness at working hardness. THE forging die material for hammers and presses. Better impact resistance than H13 but lower hot hardness. Also used as backing steel for composite dies. Applications: forging dies, die holders, press tools, shear blades, and heavy-duty punches.

High-carbon chromium-vanadium spring steel — higher C (0.55-0.62%) than 51CrV4 (0.47-0.55%) for maximum hardness and fatigue strength. V refines grain and improves temper resistance. Used for the most demanding spring applications: heavy-duty coil springs, torsion bars, stabilizer bars, and spring tools. Also used as tool steel (1.2242/59CrV4 variant).

Silicon-chromium valve spring steel — the highest fatigue life among EN 10089 spring steels. High Si (1.50-1.80%) provides excellent resistance to relaxation at elevated temperatures (up to ~250°C). Superior to 51CrV4 for high-stress, high-cycle applications. Used for automotive valve springs, heavy-duty coil springs, torsion bars, and stabilizers. ≈ AISI 9260.

Precipitation-hardening martensitic stainless steel — the highest-strength stainless in common use. Solution anneal at 1040°C then age at 480-620°C for UTS >1300 MPa. Corrosion resistance similar to 304. Cu+Nb precipitation hardening. Trade names include 17-4PH, SUS630. Used for aerospace structural parts, turbine blades, valve components, nuclear waste casks, medical instruments, and oil/gas equipment.

Nickel-chromium-molybdenum case-hardening steel. Good combination of core toughness and case hardness. The most widely used case-hardening steel in the US (AISI 8620). Used for gears, pinions, worm drives, king pins, and cross-shafts.

Super-austenitic stainless steel with high Mo and Cu content. Excellent resistance to sulfuric acid, phosphoric acid, and chloride environments. Bridges the gap between standard austenitics (316L) and nickel alloys (Inconel/Hastelloy). Used in chemical processing, oil & gas, and pharmaceutical.

Free-cutting steel with high sulfur for excellent machinability. Very similar to 11SMn30 — historical German designation that is still widely referenced. Lower C variant preferred for some screw machine products. Used for high-volume automatic lathe parts, screws, nuts, pins, and bushings. ≈ AISI 1215.

Leaded free-cutting steel — Pb (0.15-0.35%) + S (0.24-0.33%) for maximum machinability. THE ultimate Automatenstahl: machinability rating ~175% (vs 100% for 11SMn30). Pb acts as chip-breaker and tool lubricant. Used for high-speed automatic screw machine production of screws, nuts, fittings, bushings, and any part where surface finish and cycle time matter most. NOTE: Pb content being phased out under EU ELV/RoHS — replacement grades emerging.

Air-hardening cold-work tool steel. Combines good wear resistance with excellent dimensional stability during heat treatment (minimal distortion). Used for punching/blanking dies, forming tools, shear blades, gauges, and precision tooling where low distortion is critical.

Acrylonitrile Butadiene Styrene — the most widely used amorphous engineering/commodity thermoplastic. Excellent balance of toughness, rigidity, and processability. Good surface finish and paintability. Not UV-stable without additives. Trade names include Novodur (INEOS Styrolution), Terluran (INEOS), Cycolac (SABIC). Used for automotive interior trim, appliance housings (vacuum cleaners, monitors), LEGO bricks, 3D printing filament, and pipe fittings.

Cr-Mo quench-and-temper alloy steel — the lower-carbon version of 4140 (42CrMo4). Lower C (0.33-0.38%) gives better weldability and toughness than 4140 with slightly lower strength. Primarily a US/ASTM designation. Used for drill pipe, tubing, couplings, and oil field applications where weldability matters more than maximum strength.

Austenitic Ni-Fe-Cr alloy specifically developed for sulfuric acid resistance. Nb-stabilized against sensitization. Cu addition gives outstanding resistance to H2SO4 at all concentrations up to 80%. Used for sulfuric acid piping, heat exchangers, mixing tanks, pickling equipment, and pharmaceutical processing.

The most common structural carbon steel in the US. Low carbon content with good weldability and machinability. Used for buildings, bridges, construction equipment, and general structural purposes. Minimum yield strength 36 ksi (250 MPa).

The most widely used structural steel grade in the United States. 345 MPa (50 ksi) yield strength HSLA steel. Has largely replaced A36 for structural applications due to higher strength-to-weight ratio. Used for building frames, bridges, heavy equipment, and general structural fabrication.

High-strength low-alloy weathering steel. Forms a stable protective rust patina eliminating the need for paint. Cu-Cr-Ni-V composition provides 4-8x atmospheric corrosion resistance vs carbon steel. Used for unpainted bridges, architectural facades, sculptures, outdoor structures, and freight cars.

Low-carbon unalloyed steel. Excellent weldability, good formability, and low hardness. Used for pins, rivets, bushings, case-hardened parts with thin case depth, and general cold-formed components. Can be case-hardened for surface wear resistance.

Highest-carbon unalloyed spring/tool steel — C 0.95-1.05%. Maximum hardness (HRC 63-66) in the unalloyed range. On the boundary between spring steel and tool steel. Used for flat springs requiring absolute maximum hardness, doctor blades, cutting tools, cold stamping dies, and wood-working saw blades. Also known as Silberstahl (silver steel) in wire form.

Lowest practical carbon case-hardening steel — 0.07-0.13% C. After carburizing: hard surface (HRC 55-60) with extremely soft, tough core (HRC 15-20). Maximum impact absorption. Modern designation for Ck10. Used for pins, bushings, small gears, camshaft lobes, and any carburized part where maximum core toughness and ductility are critical. Also used as cold-heading and deep-drawing wire/strip.

Low-carbon unalloyed case-hardening steel. The simplest and most economical case-hardening grade. Used for lightly loaded gears, pins, bushings, rivets, and small machine parts where a hard wear-resistant surface with a soft tough core is needed.

Low-carbon unalloyed case hardening steel — 0.12-0.18% C. Between C10E (softer core) and C22E (harder core) in the case-hardening range. Good balance of surface hardness (HRC 58-62) and core toughness after carburizing. Modern designation for Ck15. Used for small gears, pins, bushings, levers, and carburized parts where moderate core strength is acceptable. Also used for cold forming and deep drawing.

Low-carbon unalloyed steel for case hardening (carburizing). 0.17-0.23% C gives a tough core with a hard, wear-resistant surface after carburizing + quenching. The simplest and cheapest case-hardening steel. Used for pins, bushings, cam followers, light-duty gears, and general machine parts where a hard surface with tough core is needed. ≈ AISI 1020.

Low-medium carbon unalloyed steel. Good balance of strength, weldability, and formability. Used for lightly loaded shafts, bolts, levers, and general machine parts. Can be case-hardened for wear applications. Between C10 and C35 in properties.

Low-carbon unalloyed steel for case hardening and general engineering — 0.17-0.24% C. After carburizing: surface HRC 55-60, soft tough core. Much cheaper than alloy case-hardening steels (16MnCr5, 20MnCr5). Modern designation for Ck22. Used for pins, bolts, levers, lightly loaded gears, and any carburized part where alloy additions are not justified. Also used as cold-heading wire.

Mid-carbon unalloyed Q&T steel — 0.27-0.34% C. Between C22E and C35E — good weldability with moderate strength after Q&T. Modern designation for Ck30. Used for lightly loaded shafts, levers, bolts, and machine parts.

Medium-carbon unalloyed steel with moderate strength. Good machinability and weldability. Used for lightly stressed components like levers, axles, bolts, and general machine parts.

Mid-carbon unalloyed Q&T steel — 0.32-0.39% C. Good balance between strength and toughness/weldability. Modern designation for Ck35. Used for moderately loaded shafts, axles, bolts, connecting rods, and machine parts where C45 would be too hard and C22E too soft. Also suitable for surface hardening (flame/induction) to HRC 50-55.

Medium-carbon unalloyed steel between C35 and C45 in properties. Good balance of strength and machinability. Used for moderately stressed machine parts, shafts, studs, axles, and crankshafts.

Mid-carbon unalloyed Q&T steel — 0.37-0.44% C. Slightly below C45E in carbon content but very similar properties. Modern designation for Ck40. Used for crankshafts, connecting rods, axles, bolts, and machine parts. Suitable for flame/induction hardening to HRC 52-56.

Medium carbon unalloyed quality steel. Good machinability and moderate strength after heat treatment. Widely used for shafts, spindles, pins, studs, and general machine parts.

Medium-high carbon unalloyed steel between C45 and C55. Good strength and wear resistance after QT. Used for springs, axles, shafts, coupling parts, and machine components where moderate hardness is sufficient without alloy steel cost.

High-carbon unalloyed Q&T steel — 0.47-0.55% C. Higher strength than C45E at the expense of reduced weldability and toughness. Modern designation for Ck50. Suitable for induction hardening to HRC 55-60. Used for heavy-duty shafts, rail wheels, clutch plates, and springs where maximum unalloyed strength is needed. Also used for agricultural equipment and wear parts.

Medium-high carbon unalloyed steel. Higher strength than C45 with reduced weldability. Used for rail wheels, agricultural equipment, springs, hand tools, and wear-resistant parts. Often used for induction-hardened components.

High-carbon unalloyed Q&T steel — 0.52-0.60% C. Modern designation for Ck55. Good strength after Q&T (UTS 800-950 MPa) and excellent surface hardness after induction hardening (HRC 56-60). Used for rail wheels, crankshafts, heavy-duty shafts, and wear parts.

High-carbon unalloyed quenching and tempering steel. High hardness and strength after heat treatment but difficult to weld. Used for springs, hand tools (screwdrivers, pliers), agricultural blades, wear parts, and railway components.

Medium-high carbon spring steel — C 0.65-0.72%. The E suffix denotes controlled S+P (<=0.025% each). Used for cold-rolled spring strip (EN 10132-4), spring wire (EN 10270-1), and flat springs. Lower C than C75S/C85S = better toughness and formability. Also used for circular saw blades, scrapers, and clips. Hardened & tempered to HRC 55-60.

Unalloyed cold-rolled spring strip steel — THE standard flat spring material. 0.65% C gives high hardness after hardening (HRC 60+). Very good fatigue properties when properly heat-treated. Much cheaper than alloyed spring steels (51CrV4, 55Cr3). Used for flat springs, circlips/snap rings, saw blades, scrapers, reed valves, and leaf springs in small dimensions.

High-carbon unalloyed spring steel. Near-eutectoid composition (0.70-0.80% C). Excellent elastic properties after hardening and tempering. Limited hardenability — effective oil quench diameter ≤12mm. Cost-effective for small/medium springs. Used for spring wire, clock springs, saw blades, retaining rings, and precision strip springs. ≈ AISI 1075.

High-carbon spring strip steel — C 0.70-0.80%. Between C67S (0.65-0.72%) and C85S (0.83-0.90%). Good fatigue strength and edge retention. Used for flat springs, leaf springs, saw blades, snap rings, and reed valves. Available as cold-rolled precision strip in hardened & tempered condition (HRC 58-62).

Highest-carbon standard unalloyed spring steel. 0.75-0.85% C gives maximum hardness (60+ HRC) among unalloyed grades but with increased brittleness. Limited hardenability — effective quench diameter ≤10mm. Used for high-hardness springs, saw blades, scrapers, and precision strip where maximum elastic limit is needed. ≈ AISI 1080.

Highest-carbon unalloyed spring strip steel — C 0.83-0.90%. Maximum achievable hardness (HRC 62-65) and fatigue strength in the cold-rolled spring strip series. Used for the most demanding flat spring applications where maximum hardness is critical: saw blades, scraper blades, precision springs, and high-frequency reed valves. Higher C than C67S (0.65-0.72%) and C75S (0.70-0.80%).

Soft martensitic (supermartensitic) stainless steel with good corrosion resistance and high toughness. Low carbon prevents embrittlement. The standard material for hydraulic turbine runners, pump impellers, compressor components, and offshore valves.

Plain carbon quenched & tempered steel — 0.57-0.65% C. Highest practical C for Q&T without excessive brittleness. Good surface hardness (HRC 55-60) with adequate core toughness. Modern designation C60E (EN 10083-2), traditional Ck60 still widely used. Used for crankshafts, connecting rods, rail wheels, axles, and machine tool spindles where alloy cost is not justified.

Phosphorus-deoxidized copper (DHP = Deoxidized High Phosphorus, 0.015-0.040% P). THE material for copper plumbing tubes worldwide (EN 1057). P prevents hydrogen embrittlement during brazing/welding — essential for plumbing/HVAC joints. Slightly lower electrical conductivity than Cu-ETP (85% IACS vs 101%) due to P content. UNS C12200. Used for plumbing tubes, heating systems, solar thermal, refrigeration tubes, and architectural roofing.

Electrolytic Tough Pitch copper — the most widely used copper grade worldwide. 99.90% Cu min with controlled oxygen content (~0.02-0.04%). Electrical conductivity ≥100% IACS. Used for busbars, motor windings, transformer coils, electrical conductors, roofing, and radiators. Caution: hydrogen embrittlement risk in reducing atmospheres above 370°C.

Oxygen-free high-conductivity copper. 99.95% Cu min with max 0.001% O — eliminates hydrogen embrittlement risk during welding/brazing in reducing atmospheres. Used for vacuum electronics, waveguides, particle accelerator components, cryogenic systems, and applications where welding in H2-containing atmospheres is required.

The premium aluminium bronze grade. Exceptional combination of high strength (700+ MPa), excellent corrosion resistance (especially seawater), and wear resistance. Used for ship propellers, heavy-duty bearings and bushings, valve bodies, pump impellers, and offshore platform components.

Standard single-phase aluminium bronze — 8% Al + 3% Fe. Good balance of strength (UTS 500-600 MPa), corrosion resistance (especially seawater), and wear resistance. Fe refines grain and improves hot working. No Ni = lower cost than CuAl10Ni5Fe4 but still excellent marine performance. Used for pump impellers, valve bodies, marine hardware, bushings, and non-sparking tools. C61400 equivalent.

Standard aluminum bronze casting alloy — 9% Al, lower Ni (3%) and Fe (2%) than CuAl10Ni5Fe4 (NAB). Good strength and corrosion resistance at lower cost than NAB. Used for valve bodies, pump casings, bearing bushings, and marine fittings where NAB-level performance is not required. UNS C95400 equivalent.

THE highest-strength copper alloy — UTS up to 1400 MPa (200 ksi), approaching steel strength with copper's conductivity (22% IACS aged). Age-hardenable: solution treat 780-800°C, age 315-340°C → HRC 38-45. Non-sparking, non-magnetic. Trade names: Alloy 25 (Materion), BeCu25 (NGK). CAUTION: Be dust is carcinogenic — machining requires extraction. Used for non-sparking tools, mold inserts, springs, connectors, and resistance welding electrodes.

Precipitation-hardened copper-iron alloy — THE semiconductor leadframe material since 1964. Fe precipitates give UTS up to 580 MPa while maintaining 60-65% IACS electrical conductivity. Resists softening to 350°C (critical for IC packaging). Also used for automotive connectors, pin grid arrays (PGA), and terminals. Trade names: Wieland K65, Aurubis PNA212.

90/10 copper-nickel alloy — the standard marine piping and condenser material. Outstanding resistance to seawater corrosion and biofouling. Used for seawater piping, heat exchangers, condensers, offshore platforms, and desalination plants. Old DIN number 2.0872.

Nickel-silicon precipitation-hardened copper — high conductivity (35-45% IACS) + high strength (UTS 600-750 MPa aged). THE lead-free alternative to CuBe2 for connectors where Be toxicity is a concern. Used for high-reliability connectors, relay springs, IC sockets, and automotive electrical contacts. Trade names: C70250 (Wieland), Corson alloy.

70/30 copper-nickel alloy — the premium marine cupronickel. Higher Ni than 90/10 (CuNi10Fe1Mn) for superior seawater corrosion resistance, especially in polluted or high-velocity water (up to 4.5 m/s). Used for condenser tubes, desalination plant tubing, propeller sleeves, seawater piping, and heat exchangers in naval and offshore service.

High-tin phosphor bronze with 10% Sn. Higher strength and wear resistance than CuSn8 but better ductility than CuSn12. Used for bearings, worm gears, thrust washers, valve guides, and marine hardware. Available as wrought and cast forms.

High-tin phosphor bronze — the strongest in the CuSn series. 12% Sn for maximum wear resistance and strength among phosphor bronzes. Difficult to cold form. Primarily used as castings or hot-formed products. Used for heavy-duty bearings, worm gears, sliding surfaces, and marine hardware.

Low-tin phosphor bronze — the standard connector and spring material in the CuSn series. 4% Sn gives good spring properties, corrosion resistance, and electrical conductivity. Better electrical conductivity than higher-Sn bronzes. Used for connectors, contact springs, switch parts, and precision bellows. ≈ UNS C51000.

Phosphor bronze with 6% tin — better cold formability than CuSn8 at slightly lower strength. Excellent spring properties and fatigue resistance. Used for electrical connectors, spring contacts, switch parts, bellows, bourdon tubes, and precision springs.

Phosphor bronze with 8% tin. High mechanical strength, excellent wear resistance, good corrosion resistance (especially seawater). Self-lubricating sliding properties. Used for heavy-duty bearings, gears, worm wheels, springs, sliding elements, and connectors.

Low-zinc brass (Tombak/Gilding Metal) — 85/15 Cu-Zn. Rich golden color, excellent cold formability, and good corrosion resistance. Lower Zn than CuZn20 — closer to pure copper in color and properties. Used for ammunition cartridge cases, decorative hardware, coins/medals, jewelry components, and architectural trim where a rich gold appearance is desired.

Gilding brass / 80-20 brass — the highest-Cu common brass. Excellent cold formability (best of all brasses), good corrosion resistance, and attractive golden color. Used for architectural trim, bullet jackets, jewelry, zippers, coins, and decorative hardware. ≈ UNS C24000.

Single-phase alpha brass — Cu 72%, Zn 28%. Excellent cold formability (deep drawing, spinning, bending). Better corrosion resistance than higher-Zn brasses (CuZn37, CuZn40). Used for cartridge cases (hence "cartridge brass"), musical instruments, lamp fittings, radiator cores, and decorative hardware. Good dezincification resistance.

Admiralty Brass — 70/28/1 Cu-Zn-Sn. The 1% Sn addition provides excellent resistance to dezincification in seawater and brackish water. THE condenser tube material for power plants and ships. Also known as Admiralty Metal. Used for condenser tubes, heat exchanger tubes, distiller tubes, and marine hardware.

70/30 Brass — the "Cartridge Brass." Best cold formability of all brasses. Excellent deep drawing properties. Good corrosion resistance (better than higher-Zn brasses). Used for cartridge cases, radiator cores, lamp fittings, musical instruments, and decorative hardware. ≈ UNS C26000.

Free-cutting leaded brass — the benchmark for non-ferrous machinability (rated 100%). Lead particles act as chip breakers for excellent surface finish. Used for screw machine parts, fittings, valves, watch components, precision mechanics, and electrical connectors. Old DIN number 2.0375.

Lead-free alpha/alpha+beta brass (63% Cu, 37% Zn). Compromise between cold formability (CuZn35) and hot formability (CuZn40). The most widely used unleaded brass. Used for cartridge cases, radiator cores, lamp components, plumbing fixtures, and decorative hardware.

Free-cutting brass with 2% lead. Good machinability (80% of CuZn39Pb3) with slightly better cold formability. Used for fittings, valves, electrical connectors, and turned parts where slightly less Pb is acceptable or required by regulation. ≈ UNS C37700.

The most widely used free-cutting brass (machinability index 100%). Excellent for high-speed automatic lathe work. Used for turned parts, faucets, valves, fittings, screws, nuts, electrical connectors, and watch components. Also known as MS58.

Muntz Metal / 60-40 Brass — at the alpha-beta boundary, the strongest common unleaded brass. Good hot workability (extrusion, forging, hot stamping). Poor cold formability vs lower-Zn brasses. Susceptible to dezincification in aggressive waters. Used for architectural extrusions, heat exchanger tubes, condenser plates, and marine hardware. ≈ UNS C28000.

Premium high-carbon high-chromium cold-work tool steel with vanadium and molybdenum. Air-hardening with minimal distortion. Superior wear resistance and edge retention. The global benchmark for cold stamping dies, blanking tools, shear blades, and forming tools.

Cold-rolled unalloyed low-carbon steel for cold forming. Base grade of the DC family (DC01-DC07). Good formability for bending, coining, beading, and simple drawing operations. Smooth surface suitable for coating and painting. Formerly designated St12.

Cold-rolled steel for moderate drawing applications. Better formability than DC01, not as good as DC04. The "middle" grade in the EN 10130 drawing steel series. Used for moderate deep-drawing applications, automotive body panels (non-critical areas), white goods housings, and general presswork.

Cold-rolled low-carbon steel for deep drawing. Higher formability than DC01/DC03 — suitable for difficult drawing and profiling operations. Used for automotive body panels, deep-drawn kitchen sinks, complex stampings, and precision-formed components.

Cold-rolled steel for extra deep drawing. The highest formability grade in the EN 10130 drawing steel series (r-value ≥1.8). Very low yield strength for excellent deep drawability. Used for complex deep-drawn automotive body panels (doors, fenders), kitchen sinks, washing machine drums, and any severe stamping application.

Interstitial-free (IF) cold-rolled steel — the absolute best formability of all automotive steels. Ultra-low carbon (<0.02%) with Ti/Nb microalloying to scavenge interstitial C and N. r-value ≥2.1. Used for the most demanding deep-drawn body panels (door inners, complex fenders, quarter panels) and structural reinforcements requiring extreme formability.

Modified D2 cold-work tool steel developed by Daido Steel (Japan). Refined Cr-Mo-V composition with higher tempering temperature capability gives ~2x the toughness of standard D2 at equal hardness (62-63 HRC). Used as D2 replacement for progressive dies, blanking tools, and cold forging where chipping is a problem.

The most widely used duplex (austenitic-ferritic) stainless steel. Balanced 50/50 microstructure provides twice the yield strength of 304/316L with superior chloride and stress corrosion resistance. Used in oil & gas, chemical processing, marine, and pulp & paper industries.

General-purpose engineering structural steel — ReH >=295 MPa. Formerly St 50-2 (DIN 17100). Higher strength than S235 but not intended for welded structures (higher C, no guaranteed weldability). Used for machine bases, frames, pins, keys, and general engineering parts where moderate strength without welding is sufficient. Not suitable for cold forming.

Highest-strength unalloyed structural steel in EN 10025-2 — former designation St60-2 (DIN 17100). Higher C and Mn than S355 giving UTS 570-710 MPa. Not intended for welding (high CEV). Used for shafts, axles, bolts, and machine parts where weldability is not required but higher strength than S355 is needed. "E" designates engineering steel (vs "S" for structural).

Highest-strength unalloyed structural steel in EN 10025-2 — ReH ≥360 MPa minimum. Not intended for welding (high C ~0.57%). Used for general engineering where maximum unalloyed strength is needed without heat treatment: machine beds, crane components, wear plates, and structural members not requiring welding. Formerly St 70-2 (DIN 17100).

Commercially pure aluminium (99.5% min Al). Excellent corrosion resistance, thermal and electrical conductivity. Very soft and easily formed. Used for chemical plant equipment, food industry, reflectors, heat exchangers, electrical conductors, and decorative trim.

Commercially pure aluminum (99.0% min Al). Excellent corrosion resistance, highest thermal and electrical conductivity among common alloys, and outstanding formability. Very low strength — not for structural applications. Used for chemical equipment, heat exchangers, fin stock, name plates, reflectors, and food/pharmaceutical packaging.

Commercially pure aluminum (99.0% min Al) — the European variant of 1100. Slightly different Si/Fe impurity limits. Same excellent corrosion resistance, conductivity, and formability. Used for heat exchanger fins, foil, chemical equipment, and general sheet applications where high conductivity and corrosion resistance matter more than strength.

The original free-cutting aluminum alloy. Al-Cu with Pb+Bi additions for chip-breaking — the highest machinability rating of any Al alloy. Being phased out in EU for RoHS compliance (Pb content). Replaced by 6026 (Bi only) or 6082 in new designs. Still widely used in US/Asia. Used for high-volume screw machine products, precision bushings, fittings, and instruments.

High-strength Al-Cu alloy, heat-treatable to high strength levels. Good machinability in T6. Poor corrosion resistance (needs cladding or anodizing). Used for heavy-duty forgings, truck wheels, aircraft structures, and general high-strength structural applications. One of the oldest aerospace Al alloys.

The original "Duralumin" — historically the first high-strength aluminium alloy. Cu-Mg composition with natural aging (T4). Good machinability and moderate strength. Largely superseded by 2024 and 7xxx alloys for aerospace, but still widely used for screw-machine parts, hydraulic fittings, and structural rivets.

Classic high-strength aerospace aluminium alloy (Al-Cu-Mg). Excellent fatigue resistance — the standard choice for aircraft fuselage skins and wing tension members. Poor corrosion resistance and weldability. Often supplied with Alclad cladding for corrosion protection. In use since 1931.

THE aerospace aluminum alloy — Al-Cu-Mg, introduced by Alcoa in 1931 as "Dural". Excellent fatigue resistance and damage tolerance. T3: UTS 400-470 MPa, good natural aging. Not weldable, poor corrosion resistance (often Alclad). Used for aircraft fuselage skins, wing skins, structural members under tension, ribs, and frames. Also: hydraulic valve bodies, gears, computer parts.

THE weldable aerospace Al-Cu alloy — Cu 5.8-6.8%, no Mg. Unique among 2xxx: fully weldable (unlike 2024/2014). Retains strength from -250°C to +315°C. Used for Space Shuttle external tank, Saturn V fuel tanks, and cryogenic vessels. T87: UTS 455 MPa. Also used for supersonic aircraft skins and high-temperature structural applications up to 315°C.

Al-Mn general purpose alloy — Mn 1.0-1.5%. ~20% stronger than 1100 pure Al with similar excellent formability, corrosion resistance, and weldability. Non-heat-treatable. THE cooking/food industry aluminum: pots, pans, beverage cans, heat exchangers, chemical equipment, and general sheet metal. Also used for roofing, siding, and storage tanks.

The most widely used manganese aluminium alloy. ~20% stronger than 1050A with similar formability and corrosion resistance. Non-heat-treatable. Used for heat exchangers, cooking utensils, pressure vessels, chemical equipment, and architectural trim.

Al-Mn-Mg alloy — THE beverage can body material. Mn 1.0-1.5% + Mg 0.8-1.3% give moderate strength (UTS 240-280 H19) with excellent formability for deep drawing and ironing. ~200 billion cans/year worldwide. Also used for roofing sheet, color-coated panels, and storage tanks. Stronger than 3003 due to Mg addition.

Al-Mn-Mg alloy with slightly higher strength than 3003. Good formability and corrosion resistance. Not heat-treatable. Commonly used for building products, mobile homes/trailers, bottle caps, and general sheet metal applications. Intermediate between 3003 and 5005 in the strength hierarchy.

Near-eutectic Al-Si brazing alloy — Si 11-13%. Lowest melting point (~577°C eutectic) in the Al-Si system = ideal brazing filler. Superior fluidity and joint fill vs 4043 (5% Si). Used as brazing sheet clad layer and wire for CAB (Controlled Atmosphere Brazing) of heat exchangers, radiators, evaporators, and condensers. Also used for welding Al-Si castings.

Low-Mg 5xxx alloy with excellent anodizing response — produces a clear, uniform anodized finish. Similar strength to 3003. Used for architectural panels, anodized trim, appliance trim, and general sheet applications where appearance after anodizing matters.

Medium-strength non-heat-treatable aluminium with excellent corrosion resistance and good weldability. Lower Mg than 5083/5754 for better formability. Used for marine components, fuel tanks, appliances, electronic chassis, and general sheet metal.

General-purpose Al-Mg alloy — Mg 2.2-2.8%. Good balance of formability, corrosion resistance, and moderate strength (UTS 210-260 H32). Non-heat-treatable — strengthened by cold work. THE most widely used 5xxx alloy globally by tonnage. Used for sheet metal work, fuel tanks, marine components, appliances, lighting, and general fabrication. Excellent weldability.

Highest-strength non-heat-treatable marine aluminum — Mg 5.0-6.0% + Mn 0.6-1.2%. ~15% stronger than 5083 in equivalent temper. Developed by Corus (now Tata Steel) specifically for fast ferry and naval vessel hulls. Trade name: Alustar. Excellent seawater resistance and weldability. Used for high-speed craft hulls, naval vessels, LNG containment, and offshore structures where 5083 strength is insufficient.

The highest-strength non-heat-treatable aluminum alloy. Al-Mg4.5-Mn with outstanding seawater and industrial chemical resistance. Retains exceptional strength after welding (unlike 6xxx/7xxx). ASTM B928 certified for marine service. THE shipbuilding aluminum — also used for rail cars, pressure vessels, cryogenic tanks, truck bodies, and LNG applications. Available O, H111, H116, H321 tempers.

The highest-strength non-heat-treatable aluminium alloy. Excellent corrosion resistance (especially seawater), good weldability. Standard alloy for shipbuilding, offshore, pressure vessels, cryogenic applications, and armour plate. Not for continuous service above 65°C under stress (SCC risk).

Marine-grade aluminium alloy with excellent seawater corrosion resistance. Higher Mg than 5052 but slightly lower than 5083 for a good strength/weldability balance. Used for shipbuilding hulls, tanks, unfired pressure vessels, and cryogenic equipment.

Al-Mg alloy — Mg 3.1-3.9%. Between 5052 (Mg 2.2-2.8%) and 5083 (Mg 4.0-4.9%) in strength. Good weldability and corrosion resistance. Approved for unfired pressure vessels (EN 13445, ASME VIII). Used for chemical storage tanks, pressure vessels, transport tankers, and marine fittings. Also used for H2 storage vessels and architectural panels.

One of the strongest non-heat-treatable Al-Mg alloys. 4.5% Mg + 0.35% Mn. THE standard alloy for beverage can lids/pull tabs (H48 temper). Also used for automotive body panels (hoods, doors), fuel tanks, and marine components. Excellent corrosion resistance and formability.

THE magnesium-aluminum welding filler wire — Mg 4.5-5.5% + Cr 0.05-0.20%. Together with 4043, accounts for the vast majority of all Al welding wire sold. ER5356/AlMg5Cr(A). Better color match after anodizing than 4043 (no dark spots). Higher weld strength than 4043. Used for MIG/TIG welding of 5xxx and 6xxx base alloys. THE filler for marine, structural, and anodized applications.

Al-Mg alloy specifically approved for pressure vessel applications (EN 13445, ASME Section VIII). Higher Mg than 5052 (2.7% vs 2.5%) with Cr addition for SCC resistance. Max continuous service temp 149°C for welded pressure vessels. Used for road tankers, chemical storage tanks, heat exchangers, and marine structures.

Medium-strength non-heat-treatable aluminium alloy with good corrosion resistance and excellent weldability. Lower Mg than 5083 for better formability. The standard alloy for automotive body panels (inner), chemical equipment, and food industry applications.

Al-Mg-Si extrusion alloy — between 6063 (softer) and 6082 (stronger) in the strength range. Optimized for medium-strength extruded profiles with good surface finish. T6: UTS 260-310 MPa. THE European rail vehicle and bus body profile alloy. Also used for structural profiles (curtain walls, ladders, scaffolding), heat sinks, and general engineering extrusions.

Medium-strength heat-treatable extrusion alloy. Slightly higher strength than 6063 with comparable extrudability. The standard alloy for railway carriages, truck bodies, and structural transport extrusions. Good weldability and corrosion resistance.

Free-machining Al-Mg-Si alloy with Bi addition for chip-breaking. Developed as Pb-free alternative to 2011 (the traditional machining aluminum). T9 temper gives excellent machinability with good strength. Used for high-volume automatic lathe parts, precision bushings, fittings, valve bodies, and screw machine products.

The most widely extruded aluminum alloy in Europe. Lower strength than 6063 but excellent extrudability and surface quality. Used for architectural profiles (window frames, curtain walls, door frames), furniture, heat sinks, and general-purpose extrusions. T6 temper for structural use; T5 for decorative.

The most widely used aluminium alloy in North America. Good balance of strength, corrosion resistance, and machinability. Heat treatable (T6). Used for structural components, automotive parts, marine fittings, bicycle frames, and general engineering. Being replaced by 6082 in European applications.

THE US structural aluminum alloy — AlMg1SiCu. Good strength (UTS 290 T6), excellent corrosion resistance, and good weldability. THE default choice in North America for structural and machined parts. Cu addition gives slightly better strength than 6082 in some tempers but slightly worse corrosion. Used for structural frames, bicycle frames, aircraft fittings, marine hardware, and general machined components.

The most common extrusion alloy worldwide. Excellent surface finish, good corrosion resistance, and exceptional extrudability. The standard choice for architectural profiles (window frames, curtain walls, railings), heat sinks, and electrical enclosures.

THE European structural aluminum alloy — AlSi1MgMn. Highest strength in the 6xxx series (UTS 310 T6). Excellent machinability, good weldability (but HAZ softening), and good corrosion resistance. THE default choice for structural aluminum in Europe — equivalent to what 6061 is in the US. Used for bridges, cranes, transport structures, offshore, and machined components.

High-strength structural aluminium alloy in the Al-Mg-Si family. One of the strongest 6xxx series alloys due to manganese addition. Replaced 6061 in many European applications. Used for trusses, bridges, cranes, transport, scaffolding, and marine applications. Heat treatable (T6/T651).

Al-Mg-Si electrical conductor alloy — optimized for maximum electrical conductivity (56-57% IACS T6) while maintaining moderate strength. THE aluminum busbar and power cable alloy. Used for high-voltage busbars, electrical conductors, overhead transmission lines, transformer windings, and switchgear. Replaces copper at 1/3 the weight and lower cost per amp-meter.

Free-machining Al-Mg-Si alloy — Pb + Bi addition for chip-breaking on CNC automatics. Same base as 6061 but optimized for high-speed screw machine production. T9: UTS 390-410 MPa. THE aluminum alloy for automatic screw machine parts: fittings, valve bodies, couplings, camera parts, and any high-volume turned Al component. Machinability rating ~90% of 2011.

Weldable high-strength 7xxx aluminium — unique because most 7xxx alloys have poor weldability. Low Cu content gives better SCC resistance than 7075. Good mechanical property recovery after welding. Used for railway carriages, military bridges, mobile cranes, aircraft freight containers, and structural transport components.

Ultra-high-strength Al-Zn-Mg-Cu alloy — Zn 7.2-8.4%, higher than 7075 (5.1-6.1%). T73 temper: UTS 510-570 MPa with improved stress corrosion resistance over T6. Used for aircraft structural forgings (landing gear, wing spars), missile components, and high-strength fasteners. Developed for thick-section forgings where 7075-T6 SCC resistance is insufficient.

High-strength aerospace aluminium developed by Alcoa for thick-plate applications. Zr addition (instead of Cr) reduces quench sensitivity for superior properties in thick sections. T7451 temper gives excellent SCC resistance + fracture toughness. Used for fuselage frames, bulkheads, wing spars, and thick structural aerospace components.

The classic high-strength aerospace aluminium alloy. Al-Zn-Mg-Cu composition provides the highest strength of all common aluminium alloys in T6 temper. Poor weldability and limited corrosion resistance. Used for aircraft structures, M16 rifle receivers, rock climbing gear, and precision mold plates.

THE aerospace aluminum — Al-Zn5.6-Mg-Cu precipitation-hardened to the highest strength of any common aluminum alloy. T6 strength rivaling mild steel at 1/3 the density. Poor weldability and corrosion resistance vs 5xxx/6xxx. Used for aircraft wing skins, fuselage frames, high-stress structural components, and competitive cycling/climbing equipment. Often Alclad for corrosion protection.

High-purity damage-tolerant Al-Zn-Mg-Cu alloy — controlled Fe+Si (<0.22% total) for maximum fracture toughness. T7351: UTS 490-530 MPa with KIc ~33 MPa√m (vs ~26 for 7075-T6). THE alloy for fatigue-critical fuselage skins where crack growth rate matters most. Used for lower wing skins, fuselage skins of wide-body aircraft (Boeing 747/777), and any primary structure requiring damage tolerance.

Ethylene propylene diene monomer rubber — THE outdoor/weather elastomer. Saturated backbone gives outstanding ozone, UV, and weathering resistance. Excellent resistance to steam, hot water, and polar solvents. NOT resistant to oils/fuels (opposite of NBR). Good electrical insulation. ρ 0.85-1.3 (lightest common rubber). Used for automotive door/window seals, roofing membranes, radiator hoses, HVAC gaskets, and pond liners.

Fluoroelastomer — THE high-temperature and chemical-resistant rubber. Outstanding resistance to oils, fuels, acids, and solvents at temperatures up to 200°C (short-term 230°C). Fluorine content (64-70%) determines chemical resistance. Trade names: Viton (Chemours), Tecnoflon (Solvay), Dai-El (Daikin). 5-10x more expensive than NBR. Used for aerospace fuel seals, chemical process seals, automotive fuel injector O-rings, semiconductor processing, and any seal exposed to aggressive chemicals at high temperature.

Cr-Mo-V hot-work tool steel — close relative of H13 with slightly lower C and V. Good hot hardness, thermal fatigue resistance and toughness. Used for forging dies, extrusion tooling, mandrels, and die-casting tools. Often preferred over H13 where higher toughness is needed.

The most widely used hot-work tool steel globally. Excellent combination of hot hardness, toughness, and thermal fatigue resistance. Used for die-casting dies (aluminum, zinc, magnesium), forging dies, extrusion tooling, and hot shear blades.

Improved version of Hastelloy C-276 with better resistance to oxidizing media and higher chromium. Considered the most versatile Ni-Cr-Mo alloy for chemical processing. Resists both oxidizing and reducing acids, chlorides, and mixed media. Used for flue gas desulfurization, pharmaceutical, and universal chemical processing.

The most versatile corrosion-resistant alloy available. Ni-Mo-Cr-W composition resists both oxidizing and reducing environments. Outstanding resistance to pitting, stress corrosion cracking, and wet chlorine gas. Used in chemical processing, flue gas desulfurization, pulp & paper, and waste treatment.

Nickel-chromium-iron-molybdenum solid-solution superalloy — exceptional combination of oxidation resistance, fabricability, and high-temperature strength. NOT age-hardenable (solid-solution only). Oxidation-resistant to 1200°C, good ductility after 16000h at 650-870°C. Outstanding formability and weldability for a superalloy. Used for gas turbine combustor cans, transition ducts, afterburners, furnace hardware, and petrochemical process equipment.

Nickel-chromium-tungsten alloy — THE combustor can material for gas turbines. Outstanding oxidation resistance to 1149°C for prolonged exposure. Excellent long-term thermal stability (no sigma/mu phase after 16000h at 649-870°C). Lower thermal expansion than most high-temp alloys. Lanthanum addition improves oxide scale adherence. Used for gas turbine combustion cans, transition ducts, furnace retorts, and catalyst grids in nitric acid production.

Standard cobalt high speed steel with 5% Co — the most widely used cobalt HSS grade. Also known as M35 or HSS-E/HSSE. Better hot hardness and cutting performance than M2, lower cost than M42. HRC 64-66 hardened. The "go-to upgrade" when M2 performance is insufficient. Used for drill bits (HSS-Co branded), taps, end mills, saw blades, and general-purpose cutting tools for stainless steel and medium-hard alloys.

Nickel-iron-chromium alloy with Mo, Cu, and Ti additions. Excellent resistance to both reducing and oxidizing acids, stress corrosion cracking, and pitting. Cost-effective alternative to pure Ni alloys. Used in chemical processing, pollution control, oil/gas recovery, and acid production.

Nickel-chromium-iron alloy — the standard engineering material for combined heat and corrosion resistance. Not precipitation hardenable. Virtually immune to chloride-ion stress corrosion cracking. Service from cryogenic to 1095°C. Used for furnace components, nuclear steam generators, chemical plant equipment, and food processing.

Nickel-chromium-iron alloy with aluminum for outstanding high-temperature oxidation resistance up to 1200°C. The Al forms a protective oxide scale resistant to spalling under cyclic thermal conditions. Better oxidation resistance than Inconel 600 (which lacks Al). Used for furnace hardware (baskets, trays, fixtures), radiant tubes, thermocouple protection tubes, catalyst support grids, and thermal reactors in automotive exhaust systems.

Nickel-chromium-cobalt-molybdenum alloy for the highest temperature service of any Inconel — continuous use to 1000°C+. Unique combination of high-temperature strength, oxidation resistance, and carburization resistance. 12% Co for solid-solution strengthening at extreme temperature. ASME Code Case N-47-28 for nuclear service to 950°C. Used for gas turbine combustors, petrochemical reformer tubes, catalyst grid supports, and next-generation nuclear heat exchangers (VHTR).

Nickel-chromium-molybdenum-niobium superalloy. Solid-solution strengthened (no precipitation hardening required). Outstanding corrosion resistance from cryogenic to 982°C. Used for jet engine exhaust systems, marine components, chemical processing, flare stacks, and nuclear applications.

High-chromium (27-31%) nickel alloy — THE nuclear PWR steam generator tube material, replacing Inconel 600 due to superior SCC resistance. Ni 58% min + Cr 30% = exceptional resistance to oxidizing media, nitric acid, and high-temperature atmospheres. Also used for coal gasification, radioactive waste processing, and sulfuric/hydrofluoric acid environments.

THE most widely used aerospace superalloy. Precipitation-hardened Ni-Cr-Fe alloy strengthened by gamma-prime and gamma-double-prime phases (Nb). Unique slow aging kinetics allow welding without cracking. UTS >1275 MPa aged. Used for gas turbine discs, jet engine components, rocket motors, cryogenic tanks, and oil/gas downhole tools. Service to 700°C.

Age-hardenable Ni-Cr-Fe superalloy for high-temperature spring and fastener applications. Strengthened by gamma-prime precipitation (Al+Ti). Oxidation and corrosion resistant to ~700°C service. Used for gas turbine springs, rocket engine thrust chambers, nuclear reactor components, and high-temp fasteners.

Liquid Crystal Polymer — self-reinforcing aromatic polyester with outstanding flow into thin walls (<0.2mm). Extremely low moisture absorption (0.02%), minimal warpage, excellent dimensional stability. Near-zero creep. Inherently flame-retardant (V-0 at 0.2mm). Very high HDT (>270°C). Trade names: Vectra (Celanese), Zenite (DuPont), Siveras (Toray). THE micro-connector and SMT-reflow-compatible polymer. Used for SMD connectors, fiber optic ferrules, chip carriers, sensors, and ultra-thin-wall electronic housings.

Lean duplex stainless steel with minimal Ni and Mo — the most cost-effective duplex grade. Uses Mn and N instead of expensive Ni for austenite stability. Double the yield strength of 304 (450 MPa vs 190 MPa). Used as a direct replacement for 304/316L where higher strength or better SCC resistance is needed.

Lean duplex stainless steel with low Mo content. More economical than 2205 with better corrosion resistance than 304/316L. Developed for construction, water treatment, and storage tanks where full duplex properties are not required.

The most widely used high-speed steel worldwide. W-Mo-Cr-V composition gives excellent red hardness (cuts at temperatures up to 600°C). Used for twist drills, end mills, taps, reamers, bandsaw blades, and general-purpose cutting tools. The benchmark HSS grade.

Cobalt super high speed steel — 8% Co for maximum hot hardness (HRC 69 at 550°C). THE HSS for machining superalloys, titanium, and pre-hardened steels where M2 burns out. Mo-series (not W-series like T15). Reaches HRC 68-70 after hardening — among the hardest HSS grades. Also known as HS2-9-1-8 (EN) or SKH59 (JIS). Used for drills, end mills, taps, broaches, and milling cutters for difficult-to-machine materials.

Nickel-copper alloy with excellent resistance to seawater, hydrofluoric acid, and alkaline environments. One of the few alloys resistant to HF acid at all concentrations. Used for marine engineering, chemical processing, oil refinery piping, and valve/pump components.

Age-hardenable version of Monel 400. Al and Ti additions enable precipitation hardening to double the strength of Monel 400. Retains excellent seawater and HF acid resistance. Used for pump shafts, impellers, doctor blades, oil well tools, and marine fasteners.

Nitrile butadiene rubber (Buna-N) — THE oil and fuel resistant elastomer. ACN content (18-50%) determines the oil resistance vs low-temp flexibility tradeoff. Higher ACN = better oil resistance but stiffer at low temp. The most widely used seal material worldwide. Used for O-rings, fuel hoses, gaskets, hydraulic seals, oil seals, and nitrile gloves. Not suitable for ozone, UV, or polar solvents (ketones, esters). HNBR variant for higher heat resistance.

Nickel-chromium age-hardenable alloy with Ti + Al for gamma-prime strengthening. Developed originally for gas turbine blades. Good creep resistance to ~700°C. Used for exhaust valves, springs at elevated temperatures, nuclear engineering fasteners, and gas turbine components. ≈ UNS N07080.

Oil-hardening cold-work tool steel. Good balance of wear resistance, toughness, and machinability at moderate cost. Very predictable heat treatment response. The standard choice for hand tools, gauges, jigs, fixtures, taps, reamers, and general precision tooling.

Pre-hardened plastic mold steel (usually delivered at 28-34 HRC). The most widely used mold base steel globally. Good machinability in pre-hardened condition, good polishability. Used for injection molds, die-casting dies, extrusion tooling, and structural mold components.

Unalloyed pressure vessel steel — THE standard boiler plate material in Europe. ReH >=265 MPa, good weldability, guaranteed elevated-temperature properties to ~450°C. "GH" = suitable for use at elevated temperatures. Used for boilers, pressure vessels, heat exchangers, and steam drums per EN 10028-2 and PED 2014/68/EU.

Mid-range pressure vessel steel — ReH >=295 MPa. Between P265GH and P355GH. Used for unfired pressure vessels, heat exchangers, and boiler components per EN 10028-2. Good weldability and guaranteed elevated-temperature yield strength. Widely specified in European process plant design.

Higher-strength pressure vessel steel — ReH >=355 MPa, guaranteed elevated-temperature properties. Between P265GH and 16Mo3 in the pressure vessel hierarchy. Used for boilers, steam drums, heat exchangers, and pressure piping operating to ~400°C. EN 10028-2, PED 2014/68/EU compliant. Good weldability.

Highest-strength normalized pressure vessel fine-grain steel — ReH >=460 MPa. "N" = normalized, "H" = elevated temperature. Used for high-pressure vessels, boiler drums, and chemical reactors where maximum strength with guaranteed elevated-temperature properties is needed. EN 10028-3 + PED compliant. Good weldability due to fine grain and controlled CEV.

Polyamide 11 — bio-based engineering thermoplastic derived from castor oil (ricinus). Lower moisture absorption than PA6/PA66 (0.9% vs 2.5-8%), better chemical resistance, and excellent low-temperature impact. 11 carbon atoms between amide groups = long aliphatic chain = more flexible/tough. Trade name: Rilsan (Arkema). Used for flexible tubing (automotive fuel/brake lines, pneumatic), offshore flexible pipes, powder coating, and SLS 3D printing (PA 2200 alternative).

Polyamide 12 — the long-chain polyamide with the lowest moisture absorption of all PA grades (0.1-0.15% vs PA6: 1.5%). Excellent dimensional stability in humid environments. Best chemical resistance among polyamides (oils, fuels, hydraulic fluids). Lowest density of all PA (1.01 g/cm³). Also the dominant 3D printing (SLS/MJF) material. Trade names include Rilsamid (Arkema), Grilamid L (EMS), TECAMID 12 (Ensinger), Vestamid L (Evonik). Used for fuel lines, brake lines, pneumatic tubing, cable sheathing, and 3D-printed functional parts.

Polyamide 46 — highest melting point (295°C) of all commercial polyamides. Short amide spacing gives high crystallinity (70%+), outstanding stiffness retention at elevated temperatures, and excellent fatigue/creep resistance. Higher moisture absorption than PA66 but better hot properties. Trade name: Stanyl (DSM/now Envalior). Used for under-hood automotive (timing chain tensioners, piston guides), EV motor insulation, connectors requiring >150°C continuous service, and SMT-solderable components.

Polyamide 6 (Nylon 6) — the most widely used engineering thermoplastic. Excellent combination of mechanical strength, toughness, wear resistance, and chemical resistance. Properties are moisture-sensitive — conditioned (50% RH) values are significantly lower than dry values. Trade names include Ultramid B (BASF), Akulon (DSM), Zytel (DuPont). Used for gears, bearings, bushings, cable ties, structural brackets, and automotive under-hood components.

Polyamide 6 with 30% short glass fiber reinforcement — the industry standard for metal replacement in structural injection-molded parts. UTS doubles vs unfilled PA6 (175 vs 80 MPa), stiffness triples (E-Mod 9.5 vs 3.0 GPa), and HDT jumps to 200°C+. The classic materialref.com differentiation case: Ultramid B3WG6 (BASF) = Zytel 73G30 (DuPont) = Durethan BKV 30 (LANXESS) = Akulon K224-G6 (DSM) = Grilon BG-30 (EMS) = Technyl C216 V30 (Domo) — all the same base material. Used for automotive brackets, engine covers, power tool housings, electrical connectors, and structural inserts.

PA6 with 50% short glass fiber — maximum common GF loading. Very high stiffness (E-Mod ~16 GPa) and strength (UTS ~210 MPa dry) approaching short-fiber-reinforced thermoset territory. Very low elongation (2-3%). High moisture sensitivity retained from PA6 base. Trade names: Ultramid B3EG10 (BASF), Zytel 73G50 (DuPont). Used for structural automotive parts (front-end carriers, pedal brackets), industrial housings, and metal-replacement applications requiring maximum stiffness at minimum cost.

Polyamide 6 with 15% short glass fiber reinforcement — moderate stiffness increase (E-Mod ~5.5 GPa vs 2.7 unfilled) while retaining good impact strength and elongation. Better toughness than higher-filled grades (GF30, GF50). Trade names: Ultramid B3EG3 (BASF), Zytel 73G15 (DuPont). Used for structural clips, housings, brackets, and under-hood automotive parts where moderate stiffness with good impact is needed.

Polyamide 610 — partially bio-based (sebacic acid from castor oil). Bridge between PA6 (high moisture) and PA11/PA12 (low moisture). Good balance of stiffness, toughness, and moisture resistance. Lower water absorption than PA6/PA66 (~1.4% saturated vs 8-9%). Used for monofilaments (brush bristles, fishing line), cable ties, automotive fluid-handling, and applications needing PA stiffness with better dimensional stability in humid environments.

Polyamide 612 — partially bio-based (dodecanedioic acid from palm kernel oil). Even lower moisture absorption than PA610 (~0.9% saturated vs ~1.4%). Better dimensional stability than PA6/PA66 in humid environments. Trade names: Zytel 151/158 (DuPont), Vestamid D (Evonik). Used for precision gears, cable ties, fuel system components, and monofilaments. Between PA610 and PA12 in the moisture/stiffness spectrum.

Polyamide 66 — stiffer and more heat-resistant than PA6. Higher crystallinity gives better creep resistance and ~40°C higher melting point (260°C vs 220°C). Slightly more brittle. More moisture-sensitive at saturation than PA6. Trade names include Ultramid A (BASF), Zytel 101 (DuPont), Tecamid 66 (Ensinger). Dominant in US/UK markets. Used for automotive engine components, electrical connectors, gears, cable ties, and industrial bushings.

PA66 with 15% short glass fiber — light reinforcement giving a good balance of increased stiffness and retained toughness. Less brittle than GF30/GF50 variants (El ~5% vs 3%). E-Mod ~6 GPa (vs 3 unfilled, 9.5 GF30). Trade names: Ultramid A3EG3 (BASF), Zytel 70G15 (DuPont). Used for structural clips, cable ties, fan shrouds, and housings where moderate stiffness increase is needed without sacrificing too much impact resistance.

Polyamide 66 with 30% short glass fiber — stronger and more heat-resistant than PA6 GF30 due to higher-Tm base polymer. UTS ~190 MPa dry, HDT ~250°C. THE automotive under-hood material for structural brackets. Trade names include Ultramid A3WG6 (BASF), Zytel 70G30 (DuPont), Durethan AKV 30 (LANXESS), Technyl A218 V30 (Domo). Used for engine brackets, radiator end tanks, air intake manifolds, and electrical connectors.

Polyamide 9T — semi-aromatic PA based on 1,9-nonanediamine and terephthalic acid. Lowest moisture absorption of any semi-crystalline polyamide (<0.3% at 50% RH). Tm 300-310°C, excellent dimensional stability. Kuraray exclusive: Genestar. Superior to PA6T in processability (lower Tm) while maintaining high-temp performance. Used for SMT connectors (reflow-compatible), automotive ECU housings, LED reflectors, and precision mechanical parts requiring minimal moisture-induced dimensional change.

Polybutylene Terephthalate — semi-crystalline polyester with fast crystallization (short cycle times), very low moisture absorption (0.15%), excellent dimensional stability, and good electrical properties. Key advantage over PA: properties nearly independent of humidity. Trade names include Ultradur (BASF), Celanex/Crastin (Celanese/DuPont), Valox (SABIC), Arnite T (DSM). Used for electrical connectors, relay housings, automotive sensors, and any precision part in humid environments.

Polybutylene Terephthalate with 30% glass fiber — THE connector and electrical component material. Key advantage over PA6 GF30: near-zero moisture absorption (0.02-0.2%), so mechanical and electrical properties are stable regardless of humidity. Lower UTS than PA6 GF30 but consistent. Trade names include Ultradur B4300 G6 (BASF), Valox 420 (SABIC), Celanex (Celanese), Crastin (DuPont). Used for electrical connectors, relay housings, coil formers, automotive sensors, and any part requiring dimensional stability in humid environments.

Polycarbonate — the transparent high-impact engineering plastic. Amorphous with outstanding impact strength (virtually unbreakable at room temp), optical clarity (~90% light transmission), and good heat resistance (Tg 145-150°C). Trade names include Lexan (SABIC), Makrolon (Covestro). Used for safety glazing, machine guards, automotive headlamp lenses, CDs/DVDs, riot shields, and electronic housings.

Polycarbonate + ABS blend — one of the most widely used industrial thermoplastic alloys. Combines PC impact strength and heat resistance with ABS processability and lower cost. Better chemical resistance than pure PC. Properties tunable by PC/ABS ratio. Trade names include Bayblend (Covestro), Cycoloy (SABIC), Pulse (Techpolymers). Used for automotive dashboards, laptop/phone housings, power tool casings, and 3D printing (FDM filament).

High Density Polyethylene — the highest-volume plastic globally (>30M tons/year). Linear chains with minimal branching give higher density and strength vs LDPE. Excellent chemical resistance, FDA/food-safe, very low moisture absorption, and good impact resistance down to -30°C. Used for pipes, bottles, containers, fuel tanks, cutting boards, playground equipment, and geomembranes.

Low-density polyethylene — branched chain structure gives flexibility, transparency, and easy processing. THE film/packaging polymer: cling wrap, carrier bags, squeeze bottles, shrink wrap. Also used for cable insulation, agricultural film, and coatings. Lower density (0.91-0.93) and strength than PE-HD but much more flexible.

Linear low-density polyethylene — short-chain branching via copolymerization with alpha-olefins (butene, hexene, octene). Better puncture resistance, tear strength, and seal strength than PE-LD at same density. THE modern stretch wrap and food packaging film. Also used for agricultural film, liners, bags, and blown film. Largely replacing PE-LD in film applications.

Ultra-High Molecular Weight Polyethylene — the highest impact-strength thermoplastic. Molecular weight 2-6 million g/mol. Self-lubricating, extremely wear-resistant (15x better than carbon steel), and chemically inert. Used for hip/knee implant bearings, conveyor guides, dock fenders, chute liners, food processing equipment, and ballistic armor (Dyneema/Spectra fiber form).

Polyetheretherketone — the premium engineering thermoplastic. Exceptional mechanical properties maintained to 260°C continuous use. Resistant to virtually all organic solvents and acids. Biocompatible (ASTM F2026). Used as metal replacement in aerospace, automotive engine parts, medical implants (spinal cages), semiconductor wafer handling, and oil/gas downhole seals.

PEEK with 30% short carbon fiber — the stiffest and strongest injection-moldable thermoplastic compound available. E-Mod ~24 GPa (vs 11 GPa GF30, 4.1 unfilled). UTS ~212 MPa. Electrically conductive (antistatic/EMI shielding). Outstanding wear/friction properties. Trade names: Victrex 450CA30, TECAPEEK CF30 (Ensinger), KetaSpire CF30 (Solvay). Used for semiconductor wafer handling, bearing cages, compressor components, and metal-replacement structural parts.

PEEK with 30% short glass fiber reinforcement. Dramatically increased stiffness (E-Mod 11 GPa vs 4.1 unfilled) and strength (UTS 160 vs 100 MPa) with reduced elongation and creep. Maintains PEEK's chemical resistance and high-temp capability (continuous 250°C). Trade names: Victrex 450GL30, TECAPEEK GF30 (Ensinger), KetaSpire GF30 (Solvay). Used for structural brackets, pump housings, valve seats, bearing cages, and semiconductor wafer handling where higher stiffness than unfilled PEEK is needed.

Polyetherimide — high-performance amorphous thermoplastic. Similar properties to PEEK at lower cost but lower impact strength and use temp. Transparent amber color. Tg 217°C, inherent flame resistance (UL94 V-0 at 0.4mm), very low smoke. Hydrolytically stable (2000+ autoclave cycles). Trade name Ultem (SABIC). Used for aerospace interior panels, medical sterilizable devices, electrical insulators, semiconductor handling, and 3D-print build plates.

Polyetherimide with 30% glass fiber — Ultem 2300 (SABIC). 2x the stiffness of unfilled PEI (E-Mod 9.5 vs 3.3 GPa) with UTS ~155 MPa. Retains PEI's inherent flame retardance (V-0), chemical resistance, and high Tg (217°C). Reduced elongation (3% vs 60% unfilled). Used for structural aircraft interior brackets, electrical connector housings, under-hood automotive, and medical device components requiring rigidity + flame retardance.

Polyethylene Terephthalate (semi-crystalline stock shape) — combines the stiffness of POM with the wear resistance of PA, without centerline porosity or moisture sensitivity. Excellent dimensional stability, low friction, very low water absorption (~0.1%). Better creep resistance than POM or PA. Widely known from bottles/packaging, but engineering PET-P is semi-crystalline and much stiffer. Trade names include Ertalyte (MCAM), Arnite (DSM), Rynite (DuPont, GF grades). Used for precision bearings in water, gears, slide elements, pump parts, and electrical insulators.

Premium aerospace precipitation-hardening stainless. Al-precipitation for the highest transverse toughness and most uniform properties of all PH stainless grades. SCC-resistant in marine environments. Used for landing gear, structural airframe parts, nuclear components, and high-performance shafts.

Polyimide — THE extreme-temperature polymer. Continuous use 250-300°C (short-term to 400°C+). Outstanding thermal stability, low outgassing, excellent radiation resistance, and self-lubricating. Available as film (Kapton, DuPont), parts (Vespel, DuPont), and moldable resin. Expensive but irreplaceable where no other polymer survives. Used for aerospace bearings/seals, semiconductor processing, flexible circuit boards (Kapton), jet engine components, and space applications.

Polymethylmethacrylate — the optical-quality plastic. 92% light transmission (better than glass). Excellent weathering resistance and UV stability. Hard but brittle (no yielding — fractures). Trade names include Plexiglas (Röhm/Evonik), Perspex (Lucite), Acrylite (Mitsubishi). Used for signs, displays, light guides, automotive tail lamps, aquariums, skylights, and protective shields.

Polyoxymethylene Copolymer — the precision engineering plastic. Exceptional dimensional stability, low moisture absorption (0.2%), low friction coefficient, and excellent machinability. More hydrolysis-resistant and chemically stable than POM-H (homopolymer). No centerline porosity in stock shapes. Trade names include Hostaform (Celanese), Ertacetal C (MCAM), Duracon (Polyplastics). Used for gears, bearings, valve bodies, pump parts, electrical insulators, and food/medical contact parts.

Acetal copolymer with 25% glass fiber — significantly improved stiffness and creep resistance vs unfilled POM-C. E-Mod ~8.5 GPa (vs 2.7 unfilled). Reduced elongation and impact. Retains POM's excellent dimensional stability, low friction, and chemical resistance. Trade names: TECAFORM AH GF25 (Ensinger), Hostaform C GF25 (Celanese). Used for precision gears, bearings, pump components, and structural parts needing higher stiffness than unfilled POM.

Polyoxymethylene Homopolymer — slightly stronger and stiffer than POM-C copolymer but with centerline porosity in stock shapes and lower resistance to hot water/alkalis. Trade names include Delrin (DuPont/DuPont de Nemours) and Tenac (Asahi Kasei). Used for gears, cams, springs, clips, fuel system components, and precision-machined parts where maximum stiffness is needed.

Polypropylene with 30% short glass fiber — a cost-effective alternative to PA GF30 for applications up to ~130°C. Much cheaper base resin (PP vs PA), zero moisture sensitivity, and excellent chemical resistance. Lower strength than PA6 GF30 (UTS 80 vs 175 MPa) but sufficient for many structural parts. Trade names include Celstran PP-GF30 (Celanese), Tepex (LANXESS), Stamax (SABIC). Used for automotive front-end carriers, battery trays, HVAC components, and household appliance frames.

Polypropylene copolymer (random or block) — better impact resistance at low temperatures than PP homopolymer (PP-H). Random copolymer: excellent clarity for packaging. Block copolymer: high impact for automotive bumpers, containers, and household appliances. Trade names: Moplen (LyondellBasell), Hostalen (LyondellBasell). THE automotive interior/exterior polymer alongside ABS.

Polypropylene Homopolymer — the lightest common engineering plastic (0.905 g/cm³). Excellent chemical resistance (esp. to acids and bases), good fatigue resistance (integral living hinges), and low moisture absorption. Becomes brittle below 0°C. Used for chemical tanks, HVAC ducts, pump housings, food containers, automotive battery cases, and medical lab equipment.

Polyphthalamide — semi-aromatic high-performance polyamide. 55%+ aromatic diacid (TPA/IPA) gives Tg ~125°C and Tm >310°C — far above PA66 (Tg 50°C, Tm 260°C). Much lower moisture absorption than aliphatic PAs. SMT-reflow compatible (260°C+). Trade names: Amodel (Solvay/Syensqo), Zytel HTN (Celanese), Ultramid T (BASF), Grivory HT (EMS). Used for automotive powertrain (thermostat housings, charge air coolers), SMT connectors, LED headlamp housings, and metal-replacement applications to 280°C.

Polyphenylene Sulfide — semi-crystalline high-performance thermoplastic. Broadest chemical resistance of any engineering plastic — no known solvents below 200°C. Inherently flame-resistant (V-0 without additives, LOI 44%). Very low moisture absorption (<0.02%). Brittle in unfilled form — usually glass-fiber reinforced for structural use. Trade names include Ryton (Solvay), Fortron (Celanese), Torelina (Toray), Durafide (Polyplastics). Used for chemical pump components, filter bags, electrical insulation, and as base resin for GF40 compounds.

Polyphenylene Sulfide with 40% glass fiber — the ultimate under-hood engineering plastic. Service to 240°C continuous, inherently V-0 flame resistant without additives, near-zero moisture absorption (<0.02%), exceptional chemical resistance (comparable to PEEK/fluoropolymers). Trade names include Ryton R-4 (Solvay), Fortron 1140L4 (Celanese), Tedur (INEOS), TECATRON GF40 (Ensinger). Used for automotive water pump impellers, thermostat housings, EGR valves, LED reflectors, and semiconductor wafer carriers.

Polyphenylsulfone — highest-performance sulfone polymer. Better impact and chemical resistance than PSU and PEI. Withstands >1000 steam autoclave cycles at 134°C without property loss. Tg 220°C. Transparent amber, colorable. Inherently flame-retardant (V-0). FDA/USP Class VI/ISO 10993 compliant. Trade name: Radel (Solvay/Syensqo), Ultrason P (BASF). Used for reusable medical instrument trays, surgical instrument handles, dental tools, aircraft interior panels, and hot-water plumbing fittings.

Polysulfone — transparent, high-temperature amorphous thermoplastic. Tg 187°C, continuous use to 160°C. Excellent hydrolysis resistance (autoclavable/sterilizable). Good dimensional stability and creep resistance. Positioned between PC (cheaper, lower temp) and PEI (more expensive, higher temp). Trade name: Udel (Solvay). Used for medical devices (sterilizable), hot water plumbing, food processing, membranes (water purification), and aircraft interior panels.

Polytetrafluoroethylene — the most chemically resistant polymer. Lowest friction coefficient of any solid material (~0.05-0.10). Service range -240°C to +260°C continuous. Cannot be melt-processed — must be sintered from powder (like ceramics). Very low mechanical strength. Trade name Teflon (Chemours/DuPont). Used for seals, gaskets, bearings, non-stick coatings, chemical reactor linings, electrical insulation, and lab equipment.

Unplasticized Polyvinyl Chloride — the second-most produced plastic globally. Hard, rigid, self-extinguishing (LOI 45%), excellent chemical resistance to acids/bases/salts, and very low cost. Key limitation: max service temp only 60°C. Developed in 1930s Germany. Used for water/sewage pipes, window profiles, electrical conduit, cladding, and chemical tanks/fittings. NOT the flexible PVC used in cables — that is PVC-P (plasticized).

Polyvinylidene Fluoride — the melt-processable fluoropolymer. Bridges the gap between PTFE (non-melt-processable) and conventional plastics. Excellent chemical resistance to acids, solvents, and hydrocarbons. Uniquely piezoelectric among polymers. Much stronger than PTFE (UTS 50 vs 25 MPa). Trade names include Kynar (Arkema), Solef/Hylar (Solvay), KF (Kureha). Used for chemical piping/valves/tanks, lithium-ion battery binder, semiconductor wet bench, architectural coatings (Kynar 500), and piezoelectric sensors.

The cheapest and lowest-grade structural steel in EN 10025-1. Only tensile strength is guaranteed (290-510 MPa), no guaranteed yield strength, composition, or impact toughness. Used for non-critical structural applications, fences, lightweight frameworks, and temporary structures where only minimum strength is needed.

Basic structural steel with guaranteed Charpy impact at 0°C (KV >=27J). Better low-temperature toughness than S235JR (which only guarantees 27J at +20°C). Same strength class (ReH >=235 MPa). Used for general structural applications in moderate climates: building frames, bridges, storage tanks, and platforms. Very widely available and cost-effective.

Basic structural steel with guaranteed -20°C impact toughness. The toughest variant in the S235 family (J2 = 27J at -20°C). Used for welded structures in moderately cold environments, general structural fabrication, and applications where S235JR's 20°C impact is insufficient.

General-purpose structural steel with minimum yield strength of 235 MPa. The most common structural steel grade in Europe for general construction, frames, and non-critical structural applications.

Structural steel with guaranteed Charpy impact at 0°C (KV >=27J). Between S235J0 and S355J0 in the strength range. ReH >=275 MPa. Very widely used in European construction: building frames, columns, beams, and general structural applications. Good weldability. Often specified as standard section material (IPE, HEA, UPN profiles).

Structural steel with 275 MPa yield and guaranteed -20°C impact toughness. Mid-range in the EN 10025-2 structural series. Used for general welded structures, cranes, conveyor frames, and building steelwork in moderate cold-climate environments.

Medium-strength structural steel with minimum yield strength of 275 MPa. Bridges the gap between S235JR and S355JR. Used for general structural applications, lattice towers, masts, and light crane components. Impact tested at +20°C (JR).

Normalized fine-grain structural steel with 275 MPa yield. The lowest strength grade in the EN 10025-3 normalized series. Better weldability and guaranteed fine-grain structure compared to standard S275JR. Used for welded structures, bridges, and general steelwork where normalized delivery is specified.

Normalized fine-grain structural steel with guaranteed -50°C impact toughness. Lower strength than S355NL but better weldability and ductility. Used for cryogenic-adjacent structures, LNG infrastructure, cold-climate bridges, and storage tanks where low-temperature toughness is critical.

Entry-level HSLA hot-rolled steel for cold forming. The lowest strength grade in the EN 10149-2 TMCP series. Good formability with guaranteed 315 MPa yield. Used for lighter-duty truck components, agricultural equipment, structural profiles, and cold-formed sections where S235/S275 is insufficient.

Non-alloy structural steel with 355 MPa min yield and 27J impact at 0°C. The "J0" variant between JR (+20°C) and J2 (-20°C). Former designation St52-3U (DIN 17100). Good weldability (CEV ≤0.47). Used for bridges, cranes, buildings, wind turbines, heavy machinery frames, and general structural applications requiring moderate low-temperature toughness.

High-strength structural steel with impact testing at -20°C (J2). Higher toughness than S355JR (tested at +20°C). Used for bridges, crane structures, offshore platforms, and cold-weather applications where impact toughness at sub-zero temperatures is required.

High-strength low-alloy structural steel with minimum yield strength of 355 MPa. Standard grade for bridges, buildings, cranes, and general structural applications. Impact tested at +20°C (JR).

Structural steel with guaranteed Charpy impact at -20°C (KV ≥40J). Same strength as S355J2 (ReH ≥355 MPa) but higher toughness: K2 = 40J at -20°C vs J2 = 27J at -20°C. Used for bridges, crane structures, offshore platforms, and welded structures in cold climates where fracture toughness at low temperature is critical.

HSLA hot-rolled steel for cold forming. Thermomechanically rolled for fine grain and good formability. The most commonly specified TMCP grade. Used for truck frames, agricultural equipment, crane booms, and structural cold-formed components.

Thermomechanically rolled fine-grain structural steel — ReH >=355 MPa with Charpy at -50°C (KV >=27J). THE workhorse for large welded steel structures in cold environments. TM rolling = low CEV = excellent weldability even in thick plate. Used for offshore platforms, wind turbine towers, bridges, crane structures, and pressure vessels. Most common TM grade by tonnage.

Normalized fine-grain structural steel. Same yield as S355JR/J2 but with guaranteed fine-grain structure from normalizing. Better weldability and impact toughness than standard S355. Used for bridges, cranes, heavy structural steelwork, and pressure vessels where normalized delivery is specified.

Normalized fine-grain structural steel with 355 MPa yield and -50°C impact toughness. The most widely used fine-grain grade in EN 10025-3. Workhorse for offshore, bridges, cranes, and wind turbine towers in cold climates. Better low-temp toughness than S355J2.

HSLA hot-rolled steel for cold forming. Between S355MC and S500MC in the EN 10149-2 strength ladder. Thermomechanically rolled for fine grain + good formability. Used for truck chassis components, crane booms, agricultural equipment, and structural cold-formed parts.

Thermomechanically rolled fine-grain structural steel — ReH >=420 MPa with Charpy at -50°C (KV >=27J). Between S355ML and S460ML in the TM strength range. Lower CEV than S420N = better weldability. Used for crane booms, offshore structures, bridge girders, and pressure vessels requiring high strength with excellent low-temperature toughness and weldability.

Normalized fine-grain structural steel — ReH >=420 MPa with Charpy at -20°C (KV >=27J). Between S355N and S460N. Fine grain from Al/Nb/V micro-alloying + normalizing. Used for bridges, crane structures, pressure vessels, and heavy structural applications where TM-rolling (ML grades) is not available or where normalizing is required by code.

High-strength normalized fine-grain structural steel. 420 MPa yield with -50°C impact toughness. Between S355NL and S460NL in the strength ladder. Used for bridges, crane structures, pressure vessels, and structural components in cold environments.

Higher-strength structural steel with 450 MPa yield, 0°C impact. Bridges the gap between S355 and S460 in the EN 10025-2 series. Used for heavily loaded structures, crane components, and building steelwork where S355 is insufficient but normalized fine-grain (EN 10025-3) is not required.

HSLA hot-rolled steel for cold forming. Between S420MC and S500MC in the EN 10149-2 strength ladder. Thermomechanically rolled for fine grain + good formability at 460 MPa yield. Used for crane booms, truck chassis, heavy agricultural equipment, and load-bearing cold-formed structures.

Thermomechanically rolled fine-grain structural steel — ReH >=460 MPa with Charpy at -50°C (KV >=27J). TM rolling = fine grain without normalizing = higher strength at lower CEV = better weldability than S460N. Used for offshore jackets, heavy crane booms, bridges in cold climates, and large welded structures needing high strength + low-temp toughness.

Highest-strength normalized fine-grain structural steel in EN 10025-3. YS 460 MPa with guaranteed weldability and impact toughness. Used for heavy crane structures, offshore platforms, bridges, and any high-load structure where normalized delivery is required.

High-strength normalized fine-grain structural steel with 460 MPa yield and impact testing at -50°C. The highest-strength grade in the EN 10025-3 normalized series. Used for offshore platforms, wind turbine towers, arctic bridges, cranes, and heavy steel structures in cold climates.

High-strength low-alloy (HSLA) hot-rolled steel for cold forming. Thermomechanically rolled for fine grain structure. 500 MPa yield strength with excellent cold formability. Used for automotive chassis, truck frames, crane booms, and agricultural equipment.

High-strength quenched and tempered structural steel — YS 690 MPa min. Part of EN 10025-6 series (S500Q to S960Q). Good weldability despite high strength (CEV controlled). Used for mobile cranes, mining equipment, truck chassis, bridge components, and any structure where weight reduction through higher strength is critical. "Q" = quenched, "L" variants add low-temp impact.

High-strength quenched and tempered fine-grain structural steel with minimum yield strength of 690 MPa. Used for heavily loaded structures like mobile cranes, mining equipment, bridges, and pressure vessels.

Shock-resistant tool steel with excellent toughness at high hardness. Air or oil hardening. Used for chisels, shear blades, punches, rivet sets, and any tooling subjected to heavy impact loading. The primary S-type tool steel in AISI classification.

The highest-strength grade in the EN 10149-2 HSLA series. 700 MPa yield with good cold formability. TMCP for ultra-fine grain structure. Used for telescopic cranes, truck frame rails, dirt-moving equipment, farm equipment, and any application requiring maximum weight reduction in cold-formed steel.

Ultra-high-strength quenched structural steel — YS 960 MPa min. Near the top of EN 10025-6 range. Approaches tool-steel-level strength while remaining weldable (with strict preheat/interpass control). Used for the most weight-critical structural applications: mobile crane booms, mining equipment, military vehicles, and specialty trailer chassis. Significantly reduces section thickness vs S355.

Styrene-acrylonitrile copolymer — AN 20-30% improves chemical resistance, heat resistance, and stiffness vs PS. Transparent (clear). Higher stiffness (E ~3.5 GPa) and HDT than PMMA. Used for housewares, cosmetic packaging, instrument lenses, battery cases, and transparent housings. THE clear engineering-grade styrenic. Also base polymer for ABS (SAN + butadiene rubber).

Silicone rubber (VMQ = Vinyl Methyl Polysiloxane) — THE extreme-temperature elastomer. Usable from -60°C to +230°C continuous (short-term +300°C). Excellent UV/ozone/weathering resistance. Biocompatible (FDA, USP Class VI). Low compression set. Electrically insulating. Lower tensile/tear strength than organic rubbers. Used for seals/gaskets, medical tubing/implants, food-grade components, baby products, automotive ignition boots, and LED/lighting encapsulation.

Super duplex stainless steel with PREN >40. Superior corrosion resistance to standard 2205 duplex, especially in chloride and H₂S environments. Used for subsea pipelines, offshore platform components, desalination plants, and chemical processing equipment.

Japanese martensitic stainless steel — the higher-carbon variant of the 420 family (C 0.26-0.40%). Achieves HRC 50-55 after heat treatment. Very good corrosion resistance for a martensitic grade. THE budget knife/cutlery steel worldwide. Also used for surgical instruments, haircutting scissors, and industrial blades. ≈ EN X30Cr13 (1.4028) / Chinese 3Cr13.

CP Titanium Grade 11 — Ti-0.12-0.25% Pd. Same mechanical properties as Grade 1 (lowest strength CP) but with dramatically improved crevice corrosion resistance in reducing acid environments due to Pd addition. Used for chemical process equipment, heat exchangers, and vessels handling HCl, H2SO4, and other reducing acids where unalloyed CP-Ti would corrode.

Titanium alloy with 0.3% Mo + 0.8% Ni — improved crevice and reducing-acid corrosion resistance over CP grades. Strength similar to Grade 2 but much better in chemical environments containing hot brines and reducing acids. More cost-effective than Grade 7 (Pd). Used for heat exchangers, pressure vessels, and chemical processing equipment in corrosive service.

Ti-6Al-4V ELI (Extra Low Interstitials) — the medical-grade version of the most common titanium alloy. Lower O, N, C, Fe limits than Grade 5 for improved fracture toughness, ductility, and biocompatibility. ASTM F136 specifies it for surgical implants. Slightly lower strength than Grade 5 but better fatigue crack growth resistance. Used for orthopedic implants (hip/knee), spinal fixation, dental implants, and cryogenic aerospace applications.

Commercially pure titanium Grade 3 — highest oxygen (0.35% max) of the CP grades = highest strength (UTS 450-550 MPa). Between Grade 2 (general purpose) and Grade 4 (maximum CP strength). Used for chemical process equipment, marine hardware, and structural components where higher strength than Grade 2 is needed but alloy cost (Ti-6Al-4V) is not justified.

Palladium-enhanced commercially pure titanium — the most corrosion-resistant Ti grade. Same mechanical properties as Grade 2, but with 0.12-0.25% Pd for dramatically improved resistance to reducing acids (HCl, H2SO4) and crevice corrosion. Premium price justified only where extreme chemical resistance is needed. Used for chemical processing equipment, desalination plants, and chlor-alkali cells.

Medium-strength alpha-beta titanium alloy — the standard for seamless tubing. 50% stronger than CP Grade 2 with better cold formability than Ti-6Al-4V. The go-to alloy for hydraulic tubing in aerospace and bicycle frames. Used for aircraft hydraulic lines, offshore risers, and sporting goods.

Near-alpha high-temperature titanium alloy. Better creep resistance than Ti-6Al-4V at temperatures above 400°C — usable to 550°C continuous. Sn and Zr are alpha-stabilizers providing solid-solution strengthening without eutectoid decomposition. THE jet engine compressor disc alloy (stages 2-7 typically). Also used for afterburner structures, blisks, and gas turbine components. Si addition (0.06-0.10%) further improves creep.

Beta-rich alpha-beta titanium alloy — higher Mo (6%) than Ti-6242 for significantly higher strength (UTS 1100+ STA). Forged beta then STA (Solution Treat + Age) for peak properties. Used for high-compressor discs and blades in jet engines where strength at 300-450°C is critical. More Beta phase than 6242 = higher strength but lower creep resistance. AMS 4981.

The most widely used titanium alloy — accounts for ~50% of all titanium production. Alpha-beta alloy with exceptional strength-to-weight ratio. Used for jet engine components, airframe structures, medical implants (hip/knee), fasteners, and racing components. Biocompatible.

Extra Low Interstitial version of Ti-6Al-4V — the standard titanium for surgical implants. Reduced O, N, C, Fe for improved ductility, fracture toughness, and biocompatibility. Used for hip and knee implants, bone screws, dental implants, spinal fusion devices, and cardiovascular stents. Also called Grade 23.

Alpha-beta titanium alloy with Nb replacing V — developed specifically to eliminate vanadium cytotoxicity concerns. Similar mechanical properties to Ti-6Al-4V but with superior biocompatibility and corrosion resistance in body fluids. ISO 5832-11 / ASTM F1295 for surgical implants. Trade name: IMI 367 (originally). Used for hip prostheses, knee replacements, fracture fixation plates, spinal devices, screws, and dental implants.

The softest and most ductile commercially pure titanium grade. Lowest O content (0.18% max) for maximum formability. Used for plate heat exchangers, chemical plant vessels, explosive cladding, deep-drawn parts, and anodizing applications. Lower strength than Grade 2 but superior formability.

The workhorse commercially pure titanium grade. Best balance of strength, ductility, and corrosion resistance among CP grades. Excellent resistance to seawater, chlorides, and oxidizing acids. Used for heat exchangers, chemical processing, marine hardware, desalination, and medical implants.

The strongest commercially pure titanium grade. Highest oxygen content (0.40% max) for maximum strength among CP grades. UTS min 550 MPa — approaches some Ti alloys. Used for airframe skins, marine hardware, surgical implants, and chemical plant components requiring higher strength than Grade 2.

Thermoplastic polyurethane elastomer — bridges the gap between rubber and rigid plastics. Exceptional abrasion resistance, high elongation (300-700%), and good oil/grease resistance. Available in wide hardness range (60 Shore A to 74 Shore D). Ester-based: better oil resistance. Ether-based: better hydrolysis/microbial resistance. Major trade names: Elastollan (BASF), Desmopan/Texin (Covestro), Estane (Lubrizol). Used for seals, hoses, cable jackets, shoe soles, phone cases, wheels/rollers, and 3D printing filament.

The simplest and cheapest tool steel — plain high-carbon steel with no significant alloy additions. Water-hardening with shallow hardening depth. Used for cold chisels, center punches, hand tools, scribers, woodworking tools, and simple cutting tools where only the surface needs to be hard.

Nickel-based gamma-prime strengthened superalloy — THE turbine disc material. Excellent creep-rupture strength up to 650°C (rotating) and 870°C (static). Developed 1950s by Pratt & Whitney. Triple-aged (solution + stabilize + precipitation) for peak properties. Superior to Inconel 718 above 650°C. Used for compressor and rotor discs, shafts, spacers, seals, rings, casings, and fasteners in gas turbine engines.

Work-hardening austenitic stainless — AISI 301. Higher C (0.05-0.15%) than 301LN enables extreme cold-work strengthening to UTS 1300+ MPa in full-hard temper. THE spring-temper stainless: used for flat springs, retaining clips, conveyor belts, automotive structural parts, and rail car body panels. Corrosion resistance similar to 304 in annealed state.

Free-cutting ferritic stainless — AISI 430F equivalent. S 0.15-0.35% + Mo 0.2-0.5% for machinability and slight improvement in pitting resistance. THE ferritic Automatenstahl for CNC screw machines. Used for screws, nuts, bushings, fittings, and automotive components where ferritische Korrosionsbeständigkeit with machinability is needed. Magnetic, not weldable.

Heat-resistant 25Cr-21Ni austenitic stainless — AISI 310S (low-C variant). Oxidation resistance to 1050°C continuous, 1150°C intermittent. Higher Cr+Ni than 304/316 = much better high-temperature scaling resistance. Used for furnace parts, radiant tubes, heat treatment fixtures, kiln linings, and thermocouple protection tubes. Also used in petrochemical cracker tubes.

Martensitic stainless for steam turbine blades and discs — 12Cr-3Ni-Mo-V. Higher Ni (2.5-3.5%) than X20Cr13 gives better toughness and corrosion resistance. V addition for creep strength at elevated temperatures. Used for LP/HP turbine blades, compressor discs, pump shafts, and valves in power generation. Service temperature to ~550°C.

High-carbon high-chromium ledeburitic cold work tool steel — AISI D2. 12% Cr + 1.5% C forms massive M7C3 carbides giving outstanding wear resistance and cutting edge retention. Air-hardening with minimal distortion. Lower toughness than H13. Used for blanking/stamping dies, thread rolling dies, cold forming tools, slitting cutters, and wear parts. Also popular as high-end knife steel.

Heat-resistant duplex (austenitic-ferritic) stainless — 25Cr-4Ni-1.5Si. Si addition improves oxidation resistance at high temperature. Used for furnace components, burner nozzles, heat treatment fixtures, and kiln supports operating at 800-1000°C. Higher strength than fully austenitic heat-resistant grades at intermediate temperatures due to duplex structure.

Martensitic CrNi stainless — AISI 431. Best corrosion resistance of ALL martensitic stainless steels due to high Cr (15-17%) + Ni (1.5-2.5%). Hardenable to HRC 46-50. Used for shafts, bolts, valve stems, pump components, fasteners in marine/offshore environments. Also aerospace (WL4044) and medical instruments. Service to 400°C.

6% Mo super austenitic stainless steel — trade name 254 SMO (Outokumpu). PREN 42-44, equivalent to super duplex but fully austenitic = non-magnetic, better weldability, wider temperature range (-196 to +300°C). Strength nearly 2× that of 300-series stainless. Used for seawater systems, offshore oil/gas, FGD scrubbers, bleach plants, and desalination where super duplex is limited by temperature or magnetic concerns.

Super austenitic 6Mo+Cu stainless — Alloy 926 / Incoloy 25-6MO. Enhanced version of 904L with higher Mo (6-7%) and N (0.15-0.25%). PREN 41-48 — rivaling super duplex but fully austenitic. Ni 24-26% eliminates stress corrosion cracking. Used for seawater systems, FGD, phosphoric acid production, offshore hydraulics, and salt extraction. Service -196 to +400°C.

Basic martensitic stainless steel — 0.16-0.25% C + 12-14% Cr. Hardenable to HRC 48-52. THE workhorse martensitic stainless: cheap, available, and adequate corrosion resistance for mild environments. AISI 420 equivalent. Used for cutlery, surgical instruments, shafts, valve spindles, bolts, and turbine blades. Better corrosion resistance than X12Cr13 (1.4006/410) due to higher C and slight Cr advantage.

12% Cr martensitic creep-resistant steel for steam turbine applications. Operates to ~580°C continuous. Combines corrosion resistance of 12% Cr with creep strength from Mo+V. Used for steam turbine blades, bolts, discs, and high-pressure steam piping in fossil power plants.

High-carbon high-chromium cold-work tool steel. Excellent wear resistance and dimensional stability after heat treatment. Used for blanking and forming dies, drawing mandrels, gauges, shear blades, and thread rolling dies. Not suitable for impact loading.

Ti-stabilized ferritic stainless with Mo — 18% Cr + 2% Mo + Ti. Best pitting resistance in the ferritic family (PREN ~25, comparable to 316L austenitics). Ti stabilization prevents sensitization after welding. Used as cost-effective replacement for 316L in hot water systems, solar collectors, catering equipment, and automotive exhaust heat exchangers. No Ni = lower cost than austenitic.

Low-cost utility ferritic stainless steel (12% Cr). A cost-effective alternative to 304 where full corrosion resistance is not required. Good weldability for a ferritic grade. Used for railway wagons, bus bodies, sugar industry, mining equipment, and structural applications.

Lean ferritic stainless with just 12% Cr and ~1% Ni — the cheapest stainless option. Also called "utility ferritic" or 3CR12. Lower corrosion resistance than 304 but much better than carbon steel. Magnetic, weldable (with precautions), and formable. Used where mild corrosion resistance at lowest cost is the goal: railway wagons, coal trucks, bus chassis, sugar mills, and architectural cladding in mild environments.

Low-carbon 18/10 austenitic stainless — AISI 304L. C max 0.030% prevents sensitization after welding without stabilizing elements. THE welding-grade 304. Slightly higher Ni (10-12.5%) than 1.4301 (304) for better austenite stability. Used for welded vessels, piping, food equipment, and any 304 application requiring post-weld corrosion resistance without solution annealing.

Higher-alloy variant of 316L — Ni 12.5-15.0% (vs 10.0-13.0 for 1.4404) and Mo 2.5-3.0%. Guaranteed delta-ferrite free (essential for pharmaceutical/biotech electropolished surfaces). THE pharma and biotech process equipment stainless. Also used for chemical plant and food processing where maximum pitting resistance in the 316-family is needed.

High-Mo, high-Ni variant of 316L. Often specified for pharmaceutical and biotech cleanroom applications where delta-ferrite must be minimized (high Ni ensures fully austenitic structure). Also used in chemical processing and offshore. Often dual-certified with 1.4404.

Super duplex stainless steel — SAF 2507 / UNS S32750. PREN >40 giving outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking in chloride environments including hot seawater. 50/50 austenite-ferrite microstructure. UTS >800 MPa — roughly 2x the strength of 316L. Used for offshore oil/gas, desalination, chemical tankers, flue gas desulfurization, and subsea equipment.

Super duplex stainless with W + Cu addition — trade name Zeron 100 (Rolled Alloys). PREN >41 — even higher than SAF 2507 (1.4410) due to tungsten contribution. Outstanding pitting, crevice, and stress corrosion cracking resistance in hot seawater and aggressive chlorides. Used for subsea oil/gas equipment, seawater desalination, FGD systems, and chemical tankers in the most aggressive chloride environments.

Low-carbon nitrogen-enhanced austenitic Cr-Ni-Mo steel — AISI 316LN. Nitrogen (0.12-0.22%) boosts yield strength above 316L while maintaining weldability. Higher PREN than 316L for better pitting resistance. Charpy impact compliant to -196°C. ASME Section III approved for nuclear pressure boundary. Used for nuclear power piping, LNG cryogenic vessels, pharmaceutical equipment, and chemical plants.

High-Mo austenitic stainless — 4-5% Mo (vs 2-2.5% for 316L). N addition for strength and PREN. Superior pitting and crevice corrosion resistance in chloride environments compared to 316L/317L. PREN ~34-38. UNS S31726 / AISI 317LMN. Used for chemical plant, pharmaceutical equipment, pulp bleach plants, and FGD systems where 316L would fail. Resistant to intergranular corrosion even after welding.

Nitrogen-alloyed work-hardening austenitic — AISI 301LN. Lower Ni (6-8%) than 304 makes it metastable: cold work transforms austenite to martensite → UTS up to 1400 MPa in full-hard condition. N addition compensates low C for corrosion and strength. Used for rail car bodies, springs, structural parts requiring high strength-to-weight ratio, and architectural cladding.

Premium hot work tool steel — higher Mo (2.7-3.2%) than H13/1.2344 (1.1-1.5%) for superior hot strength and temper resistance. Better thermal fatigue life in demanding die casting. Often specified for aluminum high-pressure die casting where H13 life is insufficient. Used for Al/Mg die casting dies, hot forging dies, and extrusion tools requiring longer life than H13.

Austenitic CrNiMo stainless — AISI 316 variant with higher Mo (2.5-3.0%) and Ni (10.5-13.0%). Better pitting resistance than standard 316 (1.4401) due to higher Mo minimum. C max 0.05% (not L-grade, so slightly higher strength than 316L). Used for chemical plant, textile dyeing equipment, and applications requiring guaranteed higher Mo than 316 minimum.

THE hot work tool steel — AISI H13 / JIS SKD61. 5% Cr + Mo + V for outstanding thermal fatigue resistance, red hardness above 40 HRC at 600°C, and excellent toughness. Air-hardening — uniform hardness in large sections with minimal distortion. Used for aluminum/zinc die casting dies, extrusion dies, forging dies, hot shear blades, and plastic molds. ESR grade available for critical applications.

Nickel cold-work tool steel with exceptional toughness from ~4% Ni content. Excellent through-hardenability, polishability, and impact resistance. Used for plastic injection molds (high-gloss), embossing dies, scrap shear blades, punches, cutlery dies, and bending tools.

Austenitic Cr-Ni stainless with higher Ni (11-13%) than 304 (8-10.5%) — AISI 305. The higher Ni content lowers work-hardening rate, making it ideal for severe cold forming and deep drawing operations where 304 would crack. Same corrosion resistance as 304. Used for deep-drawn sinks, pots/pans, complex stampings, and cold-headed fasteners where minimum work-hardening is needed.

Supermartensitic stainless steel with high Ni and Mo. Excellent combination of high strength (up to 1000 MPa) and good corrosion resistance. Superior to CA6NM (1.4313). Used for offshore flow lines, subsea Christmas trees, hydraulic cylinders, and pump shafts.

THE most widely used stainless steel worldwide — the original "18/8" austenitic (V2A). Good corrosion resistance in natural environments (water, humidity, weak acids). Non-magnetic when annealed. NOT resistant to intergranular corrosion after welding — use 1.4307 (304L) or 1.4541 (321) for welded service. PREN 17.5-21.1 — not suitable for chloride/seawater. Used everywhere: kitchen equipment, food processing, architecture, chemical tanks, automotive, medical devices.

THE standard ferritic stainless steel — 16-18% Cr, no Ni. Non-hardenable, magnetic, lower cost than austenitic grades. Good corrosion resistance for indoor/mild environments. Used for kitchen sinks, automotive trim, washing machine drums, architectural panels, and catering equipment. Not suitable for welding thick sections (grain coarsening). AISI 430.

Niobium-stabilized austenitic stainless with Mo — 316+Nb. Nb stabilization prevents sensitization (like 347) PLUS Mo gives pitting resistance (like 316). Best of both worlds for high-temperature welded chemical plant. Used for welded pressure vessels, heat exchangers, and piping operating at 400-800°C in mildly corrosive environments.

Titanium-stabilized austenitic Cr-Ni-Mo steel — AISI 316Ti. THE German standard industrial stainless (known as "V4A"). Ti prevents Cr-carbide precipitation at 450-850°C giving intergranular corrosion resistance after welding. Better high-temp stability than 316L (up to 550°C). PREN 23-27. Used extensively in chemical/pharmaceutical plants, pressure vessels, food processing, apparatus construction, and shipbuilding.

Niobium-stabilized austenitic stainless — European equivalent of AISI 347. Nb (10×C min) binds carbon to prevent Cr-carbide precipitation during welding or service at 400-800°C ("sensitization"). Same base composition as 304 but immune to intergranular corrosion after thermal cycling. Used for welded constructions in chemical plant, nuclear reactor internals, exhaust manifolds, and any 18/10 austenitic application with repeated heat exposure.

Titanium-stabilized austenitic stainless — AISI 321. Ti (5×C min) prevents Cr-carbide sensitization during welding or service at 400-800°C. Same approach as Nb-stabilized 347 (1.4550) but with Ti instead. Better creep resistance than 304/304L at elevated temperature. Used for exhaust manifolds, aircraft exhaust systems, expansion bellows, and high-temperature chemical plant (to ~800°C).

THE free-cutting austenitic stainless — AISI 303. Sulfur 0.15-0.35% for short-breaking chips and excellent machinability. Not weldable (hot cracking risk from S). Reduced corrosion resistance vs 304 due to sulfide inclusions. Used for high-volume CNC screw machine production of fittings, shafts, bushings, valves, and any turned stainless part where machining cost dominates.

High-carbon martensitic stainless steel — 0.9% C + 18% Cr. Achieves HRC 58-60 after hardening — among the hardest stainless steels. Better corrosion resistance than 440C (1.4125) due to higher Cr (17-19% vs 16-18%). THE premium European cutlery/surgical instrument stainless. Used for kitchen knives, surgical scalpels, razor blades, ball bearings in corrosive environments, and valve seats.