Abstract AISI Type H25 is a high-tungsten hot-work steel having heat resitance. It retains a high degree of working hardness at elevated temperatures. It is recommended for brass extrusion and forging dies, punches, cut-off knives, backet and dummy blocks. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-178. Producer or source: Tool steel mills.