This specification covers magnesium-alloy investment castings designated as AM100A, AZ81A, AZ91C, AZ91E, AZ92A, EQ21A, EZ33A, K1A, QE22A, ZE41A, and ZK61A. Sufficient stock shall be allowed for shrinkage and, where required, for finishing; but castings of excessive weight shall not be furnished. The castings shall conform to the chemical composition requirements prescribed for magnesium, aluminum, manganese, zinc, zirconium, rare earth elements, copper, nickel, silicon, iron, and other impurities, as determined by chemical analysis, and shall meet the specified requirements for the tensile properties such as tensile strength, yield strength, and elongation. Requirements for heat treatment and tensile test are detailed. The castings shall be of uniform quality and condition, free from cracks and other injurious defects, shall be cleaned before inspection by blasting or other approved process, and shall not be repaired by welding, impregnation, peening, or other method unless it is required.