Martensitic Stainless Steel
Martensitic stainless steels combine stainless chromium levels with sufficient carbon to permit hardening by heat treatment.
Composition & metallurgy
Typically 11.5–18% chromium with carbon ranging from low levels in tough grades to high levels in wear-resistant grades. Nickel and molybdenum may be added.
Common grades
410, 420, 431, 440A, 440B and 440C.
Applications
Turbine parts, pump shafts, valves, cutlery, surgical instruments, bearings, blades, molds and wear components.
Engineering characteristics
Can achieve high hardness and strength, but corrosion resistance is generally below austenitic or duplex stainless. Tempering condition controls toughness and service performance.
Known manufacturers
Specialty producers include Outokumpu, Acerinox, Aperam, Daido Steel, Nippon Steel-related stainless operations, Jindal Stainless and Asian specialty mills.
Specification checks
Confirm the current standard revision, exact product form, heat-treatment condition, mechanical properties, impact requirements where applicable, corrosion environment, welding procedure, dimensions, tolerances, NDT and mill test certification. Similar designations across standards are not automatically equivalent.
Element Folio engineering reference. Manufacturer examples are indicative and product availability changes by plant, region and year.

