Heppenstall Gr. 5M21 is a low-carbon, high-molybdenum and nickel precipitation hardening die steel developed especially for hot working of ferrous and nonferrous metals in press and upsetting machines. It is furnished to the Die Steel trade under the trade name of Prestem (in the prehardened condition) and Presneal (in the annealed condition). This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-187. Producer or source: Midvale-Heppenstall Company.