SOLAR TOOL STEEL is a very tough water hardening tool steel. Even at Rockwell C 59/60, it will bend before breaking. If medium and large sections, the steel develops a hard case and tough core when hardened. This datasheet provides information on composition, physical properties, and hardness. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-32. Producer or source: Carpenter. Originally published as Solar, April 1955, revised September 1991.