HD steel is a kind of high toughness, air cooling hardening hot working die steel. HD steel has good high temperature strength and toughness, high temperature hardness, thermal stability and thermal fatigue resistance.
HD steel is often used for hot extrusion punch of steel medicine pipe, extrusion bottom die and perforation needle of copper alloy pipe, hot extrusion bearing punch and concave die, valve extrusion low die and so on. The service life is longer than that of H21 steel.
