Materials database

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.

Low-carbon molybdenum-bearing austenitic stainless steel, widely known as AISI 316L. The Mo addition (2–2.5%) significantly improves resistance to pitting and crevice corrosion compared to 1.4301 (304). Low carbon content (max 0.03%) ensures resistance to intergranular corrosion after welding without post-weld heat treatment. Standard grade for pharmaceutical, petrochemical, chemical and marine applications. PREN 23–29.

Low-carbon austenitic stainless steel with 2.5-3.0% Mo — the higher-Mo variant of 1.4404 (316L). The increased Mo (vs 2.0-2.5% in 1.4404) provides superior pitting and crevice corrosion resistance in chloride environments. Ultra-low carbon (≤0.03%) prevents sensitization during welding. Used for chemical processing equipment, pharmaceutical vessels, offshore piping, marine hardware, and pulp & paper digesters where 1.4404 is borderline. Often specified in pharmaceutical/biotech where maximum corrosion resistance is required.

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.

Nitrogen-strengthened low-carbon austenitic stainless steel — essentially 316LN. The N addition (0.12–0.22%) raises yield strength to ≥280 MPa (vs 200 for 316L) without sacrificing corrosion resistance or weldability. Preferred over 316L for pressure vessels and cryogenic applications where higher design stress is needed. Approved for ASME Section VIII. Used for chemical reactors, pharmaceutical vessels, cryogenic storage (LNG) and high-pressure piping.

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.

High-molybdenum austenitic stainless steel with 4.0-5.0% Mo — significantly higher than 316L (2.0-2.5%). Provides substantially improved resistance to pitting and crevice corrosion in chloride environments (PREN ~35, vs ~25 for 316L). Low carbon (≤0.03%) and N addition for sensitization resistance and strength. Used for chemical processing in aggressive chloride media, flue gas desulfurization, pulp & paper bleach plants, and seawater-cooled heat exchangers where 316L is insufficient but duplex is not desired.

The most widely used duplex stainless steel worldwide (SAF 2205 / UNS S31803/S32205). Austenitic-ferritic microstructure provides ~2× yield strength of 304/316 (≥450 MPa) with excellent resistance to stress corrosion cracking, pitting (PREN 33-38), and intergranular corrosion. Service temperature -50°C to 300°C. Used for oil & gas production tubing, chemical processing vessels, desalination plants, pulp & paper digesters, heat exchangers, and bridge structures. Weldable with ER2209 filler.

Super duplex stainless steel (SAF 2507 / UNS S32750) with 25% Cr, 7% Ni, 4% Mo, and high N for PREN ≥42. The highest corrosion resistance and strength among standard duplex grades — YS ≥550 MPa is ~2.5× that of 316L. Service temperature up to 300°C. Used for subsea oil & gas equipment (manifolds, trees, risers), desalination plants, flue gas cleaning, chemical tankers, and mining equipment in severe chloride environments. Requires careful welding to avoid sigma phase.

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.

Lean duplex stainless steel (SAF 2304 / UNS S32304) with reduced Mo and Ni content compared to 2205. Cost-effective alternative to austenitic 316L with ~2× yield strength (400 MPa) and good stress corrosion cracking resistance. No Mo addition — relies on Cr+N for corrosion resistance (PREN ~25). Used for storage tanks, water heaters, transport tanks, structural applications in construction (e.g. reinforcing bar), and swimming pool structures. The budget-friendly duplex option.

Titanium-stabilized ferritic stainless steel with 12% chromium, often called the muffler grade stainless steel. Ultra-low carbon (max 0.03%) with Ti stabilization prevents sensitization during welding. Excellent formability for stamped and deep-drawn components. Primary material for automotive exhaust systems (manifolds, catalytic converter housings, mufflers), hot water heaters, and welded tubes. Cost-effective alternative to austenitic grades. Service temperature up to 600°C.

Ti- and Nb-stabilized ferritic stainless steel with very low carbon (max 0.03%) and 17.5-18.5% Cr. The dual stabilization with Ti and Nb provides excellent resistance to intergranular corrosion and superior high-temperature oxidation resistance. Non-hardenable. Used extensively for automotive exhaust manifolds, catalytic converter housings, heat exchangers, furnace parts, and kitchen equipment. More economical than austenitic grades for high-temperature applications.

Martensitic chromium stainless steel with moderate carbon content (0.26-0.35%) and 12-14% Cr. Part of the AISI 420 family. Can be hardened to approximately 50-52 HRC. Good balance of hardness, toughness, and corrosion resistance. Used for cutlery, kitchen knives, scissors, springs, surgical instruments, and pump shafts. Better toughness than higher-carbon variants X39Cr13 and X46Cr13.

Tungsten-alloyed hot work tool steel (AISI H21) with 9% W for exceptional high-temperature strength and resistance to tempering. Low thermal conductivity makes rapid cooling unacceptable — tools must be preheated to ~300°C before use. Achieves 44-50 HRC. Used for die casting dies for copper alloys (brass/bronze), hot forging dies, hot extrusion tooling, hot shear blades, and mandrels. The go-to steel for copper alloy die casting where H13 would soften. JIS: SKD5.

Chromium-molybdenum hot work tool steel (AISI H10) with high Mo content for excellent resistance to thermal softening and thermal fatigue. Can be safely water-cooled in service, unlike tungsten hot work steels. Achieves 50-52 HRC. Used for hot forging dies, die casting dies (especially aluminum), hot extrusion tools, hot punches, and hot shear blades. Superior thermal fatigue resistance compared to H11/H13 in continuous high-temperature service above 600°C. EN designation: 32CrMoV12-28.

Pre-hardened corrosion-resistant mould steel (30–36 HRC as delivered). 16% Cr provides stainless-like corrosion resistance — no surface pitting during storage, no rust contamination of moulded parts. Sulfur addition improves machinability. Used for moulds processing corrosive plastics (PVC, acetals, flame-retardant compounds), food packaging moulds, moulds stored in humid environments and prototype tooling. Can be directly machined in pre-hardened state without additional heat treatment.

Chromium hot work tool steel, known as AISI H11. Similar to 1.2344 (H13) but with lower V content (0.30–0.50% vs 0.85–1.15%) giving better toughness at the expense of slightly lower wear resistance. Better suited for applications requiring maximum toughness — large forging dies, die casting dies for light alloys, extrusion tools. Air-hardening to 50–54 HRC. Preferred over H13 when thermal shock resistance is the primary concern.

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.