COPPER ALLOY No. 647 is an age-hardenable copper-nickel-silicon alloy which can be age hardened to strength levels equivalent to those of many alloy steels. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-230. Producer or source: Copper and copper alloy mills.