This specification covers tool steel compositions appropriate for usable shapes cast by pouring directly into suitable molds and for master heats for remelting and casting. Grades of the tool steel covered in this specification include air- and oil-hardening grades such as CA-2, CD-2, CD-5, CM-2, CS-5, CS-7, CH-12, CH-13, and CO-1. The steel shall be made by one or more of the following processes: electric-arc furnace or induction furnace and may be argon-oxygen decarburization refined. Each of the steel shall undergo chemical analysis and shall conform to the chemical composition specification for carbon, manganese, silicon, sulfur, phosphorus, chromium, molybdenum, vanadium, cobalt, tungsten, and nickel. Material shall be packed and marked with heat or lot number, specification number, steel type, and form to ensure safe delivery and proper identification.

1.1 This specification covers tool steel compositions for usable shapes cast by pouring directly into suitable molds and for master heats for remelting and casting.

Note 1—A master heat is defined as any single heat of steel of certified analysis which has been processed into suitable form (shot, ingot, etc.) for remelting. A uniform blend of master heats is also acceptable for remelting. This blend is defined as a master heat lot and its average chemical composition shall be certified.

1.2 Nine grades, CA-2, CD-2, CD-5, CM-2, CS-5, CS-7, CH-12, CH-13, and CO-1, are covered in this specification.

Note 2—The committee formulating this specification has included air- and oil-hardening grades of tool steel that have been extensively used. Other compositions will be considered for inclusion as the need arises.