COPPER Alloy No. 770 is a spring quality copper-nickel zinc alloy having high resistance to corrosion. It is recommended primarily for optical goods, springs, resistance wire, hardware and similar products. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-185. Producer or source: Copper and copper alloy mills.