The information in this report covers data relating to SAE J438, Tool and Die Steels, and is intended as a guide to the selection of the steel best suited for the intended purpose and to provide recommended heat treatments and other data pertinent to their use. Specific requirements as to physical properties are not included because the majority of tool and die steels are either worked or given special heat treatments by the purchaser. The purchaser may or may not elect to use the accompanying data for specification purposes.