Steel grades

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.

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.

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.

High-chromium ferritic stainless steel (23–26% Cr) with aluminum (1.2–1.7%) and silicon (0.7–1.4%) additions for maximum scaling resistance up to 1150°C. The highest oxidation resistance among ferritic stainless steels. Non-hardenable. Resistant to sulfur compounds and reducing gases. Used for furnace linings, kiln rollers, burner parts, thermocouple protection tubes, steam boiler superheater elements, and extreme-temperature components. Equivalent to AISI 446.

High-chromium creep-resistant martensitic steel equivalent to ASTM Grade 91 (P91/T91/F91). V and Nb additions with controlled N provide exceptional creep rupture strength at temperatures up to 580°C. The foundation steel of modern ultra-supercritical (USC) power plants worldwide. Used for main steam pipes, boiler headers, superheater tubes, and high-temperature pressure components in fossil and nuclear power generation.

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.

Advanced creep-resistant martensitic steel equivalent to ASTM Grade 92 (P92/T92/F92). Improved version of P91 with 1.5-2.0% tungsten addition for 25-30% higher creep rupture strength. Currently the strongest commercially available steam pipe steel. Enables ultra-supercritical power plant operation up to 300 bar / 600°C. Used for main steam pipes, headers, and pressure components in the most advanced fossil power plants worldwide.

Basic martensitic stainless steel with 12% chromium — the DIN/EN designation for AISI 410. Heat-treatable to a wide range of mechanical properties from soft-annealed (≤730 MPa) to quenched and tempered (650–850 MPa in QT650). Good scaling resistance up to 650°C. Used for cutlery, surgical instruments, turbine blades, shafts, bolts, valve components, and pump parts. Machinability similar to carbon steels at same hardness.

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.

Free-cutting martensitic stainless steel with sulfur addition for improved machinability. Equivalent to AISI 416. Based on X12Cr13 (AISI 410) composition with 0.15-0.35% S added. Can be hardened by heat treatment. Corrosion resistance is somewhat reduced compared to non-free-cutting grades but improves in the quenched and tempered condition. Used for automatic screw machine parts, valves, fittings, bolts, nuts, pump components, and precision turned parts.

Free-cutting martensitic stainless steel with Mo and S additions. Equivalent to AISI 430F. Higher Cr (15.5-17.5%) and Mo addition provide better corrosion resistance than X12CrS13 while maintaining excellent machinability from S content. Used for automatic screw machine parts, fasteners, valve bodies, pump shafts, and precision components requiring both corrosion resistance and easy machining.

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 austenitic stainless steel with high silicon content (1.5–2.5%) for exceptional scaling resistance up to 1000°C. The silicon creates a protective SiO₂ layer supplementing the chromium oxide barrier. Excellent resistance to carburization and sulfidation. Used for furnace parts, burner nozzles, kiln furniture, hardening boxes, annealing baskets, and high-temperature industrial process components. Equivalent to AISI 309.

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.