CPM REX 71 is a super high-speed steel that can be heat-treated to hardnesses up to Rockwell C 70. It is now made exclusively by Crucible's particle metallurgy process. Its high hardness, fine grain size and uniform distribution of small carbides make it outstanding for special-purpose cutting tools. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-252. Producer or source: Crucible Specialty Metals Division, Colt Industries.