Abstract REPUBLIC RSM 250 is an 18% nickel-cobalt-molybdenum age-hardening steel designed to develop 250,000 psi yield strength with good toughness. It is recommended where a combination of strength, toughness and notch resistance is required such as aircraft landing gears and jet engine components. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength 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, joining, and surface treatment. Filing Code: SA-250. Producer or source: Republic Steel Corporation, Titanium Division.