Abstract REX M3S-2 is a sulfur-bearing high-speed tool steel offering very good abrasion resistance and resistance to softening at elevated temperatures. CPM REX M3S-2, produced by the Crucible Particle Metallurgy process, is an improved-quality product with finer grain size, better toughness and better grindability than the conventionally produced REX M3S-2. Other characteristics and properties of the two products are very similar (See General Characteristics for more details). This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-260. Producer or source: Crucible Specialty Metals Division, Colt Industries.