Stainless Steel

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 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Martensitic chromium stainless steel with medium-high carbon content (0.36-0.42%) and 12.5-14.5% Cr. Higher hardness potential than X30Cr13 (up to 54 HRC) but slightly reduced toughness. Used for high-quality cutlery, cutting tools, scissors, surgical instruments, and measuring tools requiring both corrosion resistance and good edge retention.

Hardenable martensitic stainless steel with Mo addition for improved corrosion resistance and hardenability. Higher Cr (15.5-17.5%) than basic Cr13 grades. Achieves 220-275 HB after QT. Good resistance to nitric acid, water, steam, acetone, alcohol, and glycerine. Used for pump shafts, valve components, springs, fasteners, turbine blades, and food processing equipment requiring both hardness and corrosion resistance.

Low-carbon martensitic stainless steel with nickel (3.5–4.5%) and molybdenum (0.3–0.7%) for improved toughness, weldability, and corrosion resistance. Available in QT650, QT780, and QT900 conditions. Primary material for hydraulic turbine runners (Francis, Kaplan), pump impellers, compressor components, and offshore parts. Service range -60°C to 300°C. Also known as F6NM (ASTM cast) and UNS S41500.

Martensitic chromium stainless steel with high carbon content (0.43-0.50%) and 12.5-14.5% Cr. The highest carbon grade in the basic Cr13 martensitic series. Achieves hardness up to 56 HRC. Good compromise between hardness and corrosion resistance. Equivalent to AISI 420C/420HC. Used for knife blades, surgical instruments, razor blades, CO2 capture pipes, and precision cutting tools. Good polishing capability.

Free-cutting high-carbon martensitic stainless steel. Sulfur-enhanced variant of X46Cr13 (1.4034) for automated production of knife blades and cutlery. Combines the high hardness of X46Cr13 (up to 54 HRC) with excellent machinability for mass production on automatic lathes and CNC machines. Used for industrially manufactured knife blades, scissors, and cutting tools.

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.

Premium martensitic stainless steel with 0.50% C, 15% Cr, Mo and V additions. The signature blade steel of German knife manufacturers (Wüsthof, Zwilling J.A. Henckels, Victorinox Swiss Army). Mo and V improve corrosion resistance, hardenability, and toughness beyond basic Cr13 grades. Achieves 55-57 HRC. Excellent rust resistance, easy sharpening, and good edge retention. Also known as Krupp 4116. Equivalent to 5Cr15MoV (Chinese).

High-carbon martensitic stainless steel with Mo addition for blades and cutting tools. Higher carbon (0.48-0.60%) than X50CrMoV15 with similar Cr and Mo but without V. Achieves high hardness (56-58 HRC) with excellent wear resistance. Used for premium knife blades, scissors, surgical instruments, and industrial cutting tools. Popular in Japanese-influenced European knife manufacturing.

Ultra-high-carbon martensitic stainless steel for maximum hardness and edge retention. The highest standard carbon content (0.60-0.75%) among EN 10088 martensitic grades with Mo addition. Achieves 58-60 HRC. Superior wear resistance and edge sharpness. Used for premium razor blades, surgical scalpels, industrial cutting tools, and high-performance knife blades where maximum edge retention is critical.