400 Series Stainless Steel

Martensitics are low carbon steels built around the Type 410 composition of Iron, 12% to 15% Chromium, and 0.08% to 0.50% Carbon. These grades can be heat treated, hardened and are often tempered to give good hardness and high toughness. Untempered martensite is low in toughness and therefore brittle. Type 431 has the addition of Nickel to further improve the properties. Martensitic steels have moderate corrosion resistance, but poor compared to austenitics.


Martensitics are often used when hardness is critical (knives), where surface hardness creates a sharper blade, medical tools (scalpels, razors, internal clamps), gears, valves, pumps, shafts, bearings and turbine parts.