CPM REX M4 is a special-purpose high-speed steel designed to give high wear resistance in tools. It is made exclusively by Crucible's particle metallurgy process which imparts excellent quality and grindability. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-264. Producer or source: Crucible Specialty Metals Division, Colt Industries.