This 2/3 nickel and 1/3 copper material is an alloy developed by the Special Metals Corporation. It has very good strength and is similar in strength to medium carbon steel, however, due to its strength it has poor machining properties. Its composition also provides it with excellent corrosion resistance in specific highly corrosive environments of sea water, hydrofluoric acid, sulfuric acid, alkalines. With the ability to retain its strength at very high and low temperatures it is one of the best materials to resist extreme elemental conditions. Applications include marine fasteners and chemical processing.