Abstract Carpenter Custom 630 is a martensitic precipitation (age) hardening (PH) stainless steel offering high strength and hardness along with excellent corrosion resistance. It has good fabricating characteristics and can be age hardened by a single-step, low-temperature treatment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-258. Producer or source: Carpenter. Originally published August 1971, revised December 2000.