ELEKTRON QH21A is a magnesium-base casting alloy developed to meet the ever increasing requirements for casting alloys to operate at elevated temperatures. It is of particular interest to designers and stress engineers for highly stressed components operating at temperatures up to 480 F (250 C), especially where pressure tightness is a requirement. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: Mg-72. Producer or source: Magnesium Elektron Inc..