gunmetal

thumb|Gunmetal parts

Gunmetal, also known as red brass in the United States, is a type of bronze – an alloy of copper, tin, and zinc. Proportions vary, but 88% copper, 8–10% tin, and 2–4% zinc is an approximation. Originally used mainly for making guns, it has largely been replaced by steel for that purpose. Gunmetal casts and machines well, and is resistant to corrosion from steam and salt water. It is used to make steam and hydraulic castings, valves, gears, statues, and various small objects, such as buttons. It has a tensile strength of to , a specific gravity of 8.7, a Brinell hardness of 65 to 74, and a melting point of around 1,000 degrees Celsius.