DOWMETAL R and DOWMETAL RC, the die casting alloys in most general use, are the 9% A1, 1% Zn magnesium alloys AZ91A and AZ91B. They combine good mechanical properties, good casting characteristics and good resistance to corrosion. A variation, designated as Dowmetal AZ91C, is used for sand and permanent mold castings. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, machining, and surface treatment. Filing Code: Mg-17. Producer or source: The Dow Chemical Company.