Bronze

A generic name for a group of copper-based alloys. Historically, bronze is a copper rich, copper-tin alloy whose use can be traced back to 5000 BC. The term bronze now applies to a wide range of copper alloy compositions, including many binary alloys, aluminum bronze, beryllium bronze, manganese bronze, silicon bronze, all of which are essentially tin-free. At times, trace elements such as zinc, phosphorus and lead are added to enhance properties for specific applications. Bronze is used for screws, wire hardware, wear plates, bushings and springs. It also is used for trolley wire because of its high strength, high electrical conductivity and good wear resistance. It is somewhat stronger than copper and brass and has equal or better ductility.