Materials database

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).