Superplast 300, also known as SP 300, is a prehardened steel for mold service. It is designed to provide improved weldability and machinability compared to conventional P20 steel. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-643. Producer or source: Industeel USA, LLC.