Abstract HS-100 is a super high-speed steel built on an AISI Type M33 base but with higher carbon and cobalt. It is able to attain an approximate hardness of Rockwell C 68 with normal heat treatment. It gains its great resistance to wear from its high hardness rather than from excess vanadium carbides. HS-100 is recommended for applications where long production runs or heavy-duty machining is involved. This datasheet provides information on composition and hardness. It also includes information on forming, heat treating, and machining. Filing Code: TS-429. Producer or source: Latrobe Steel Company.