MAGNESIUM HM21A is a magnesium alloy sheet, plate, and forging material developed for high temperature service as in aircraft and missile applications. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and bearing strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Mg-46. Producer or source: The Dow Metal Products Company.