Abstract AISI No. 630 is a precipitation hardening stainless steel which is used in a variety of applications requiring strength combined with corrosion resistance. It is recommended for chemical process equipment, valve parts, aircraft fittings, pump shafts, etc. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness, creep, and fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-156. Producer or source: Various alloy steel mills (licensed).