Panther Special is a cobalt high-speed steel recommended for heavy duty cutting of hard, gritty materials, such as cast iron as well as heat treated alloy steels. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-180. Producer or source: Allegheny Ludlum Corporation.