ATI S240 is an age-hardening martensitic stainless steel with strength and toughness comparable to other commercial steels in the class, but with improvements. The 240 in the title is the tensile strength. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1107. Producer or source: ATI Allvac.