C70600 (C706) & C71500 (C715), Copper nickel offers excellent corrosion resistance, especially in marine salt water environments. The main, wrought copper-nickel alloys chosen for sea water service contain 10 or 30 percent nickel. They also have important additions of iron and manganese which are necessary to maintain good corrosion resistance. Some of the primary uses for C706 include copper nickel fittings (CuNi Fittings) as well as condensers and exchanger shells.