REX M7 is a molybdenum type of high-speed steel designed with higher carbon and vanadium than that in AISI Type M1 to provide higher hardness after heat treatment and improved wear resistance. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-309. Producer or source: Crucible Specialty Metals Division, Colt Industries.