Copper Alloy No. C70400 is a 5.5% nickel-copper alloy characterized by resistance to corrosion by high-velocity seawater, resistance to stress-corrosion cracking, and retention of strength at moderately elevated temperatures. It responds well to both hot and cold-working operations. Among its many uses are springs, switches, heat exchangers, salt-water piping and relays. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-500. Producer or source: Copper and copper alloy mills.