ALUMINUM 355 is a heat treatable aluminum alloy containing silicon and copper as the major alloying elements. It is recommended for light weight, high strength, pressure tight castings. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on high temperature performance as well as heat treating, machining, and joining. Filing Code: Al-18. Producer or source: Aluminum Company of America.