Abstract AISI Type H26 hot-work tool steel is the 18 tungsten-4 chromium-1 vanadium high-speed composition with lowered carbon to provide a high-degree of toughness. It has high red hardness and good resistance to abrasion. It is preferable to the conventional hot-work tool steels for applications in which higher hardness must be maintained at elevated temperatures. It is also recommended in cold-work that involve long runs, but should not be used where liquid cooling is required. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-294. Producer or source: Tool steel mills.