CarTech 431 stainless is designed to provide improved corrosion resistance and toughness in a quench-hardenable stainless steel. It has been used for parts such as aircraft fasteners and fittings and should be considered for structural members exposed to marine atmosphere. Mechanical properties include excellent toughness (impact strength) at relatively high hardness level. It offers the best corrosion resistance of the conventional martensitic stainless grades. Considerable quantities of this steel have been produced to MIL-S-18732, and AMS-5628.

CarTech 431 stainless has been used for highly stressed aircraft components including fasteners, bomb racks, bolting, pump shafts, valve stems, etc. It should be considered for applications requiring the optimum combination of corrosion resistance, hardness and toughness from approximately -100 to 1200°F (-73 to 650°C).