Gunmetals, also more prevalent in Europe and sometimes called “red brass” in the United States, are tin bronze castings that have been widely used in shipbuilding and marine engineering. The addition of a small amount of zinc improves castability. The alloys are resistant to corrosion from steam and salt water and are not prone to dezincification, stress corrosion, crevice corrosion or pitting. Gunmetal alloys are used to make steam and hydraulic castings, valves, pump parts, steam fittings, gears, bearings, statues, and small objects such as buttons. Modern admiralty gunmetal is composed of 88% copper, 10% tin, and 2% zinc.
References
- Copper Alloys for Marine Environments, Carol Powell and Peter Webster, Publication 206, Second Revision, , CDA UK, .
- Introduction to Brasses (Part I), An overview of the large and industrially important family of alloys based on copper and zinc. The article is especially recommended to designers, engineers and others who specify materials for manufactured products. A brief history of brasses is included for those interested in learning about these interesting alloys. Links are provided to sources on The Copper Page and other websites where more detailed information can be obtained. .
- Introduction to Brasses (Part II), This section provides explanations about duplex, free cutting and high strength brasses as well as alloying agents and European designations .