Gilding metal
Gilding metal is a form of brass (an alloy of copper and zinc) with a much higher copper content than zinc content. Exact figures range from 95% copper and 5% zinc[1] to “8 parts copper to 1 of zinc” (11% zinc) in British Army Dress Regulations.[2]
Gilding metal is used for various purposes, including the jackets of bullets, driving bands on some artillery shells,[3] as well as enameled badges and other jewellery. The sheet is widely used for craft metalworking by hammer working.[1] It is also used particularly as a lower-cost training material for silversmiths. Starting in 1944, shell casings made of gilding metal were melted down by the United States Mint to be made into pennies.[4] These pennies replaced the less popular steel cent of 1943, and the pennies of this composition were produced until 1946.
Gilding metal may be annealed by heating to between 800–1,450 °F (427–788 °C).[5] It should be cooled slowly afterwards, to reduce risk of cracking.[6]
References
- Untracht, Oppi (1968). Metal Techniques for Craftsmen. p. 18. ISBN 0-7091-0723-4.
- War Office (1904) Dress Regulations for the Officers of the Army (Including the Militia). London: HMSO. p. 4
- "105mm Advanced Cannon Artillery Ammunition Program (ACA2P) § 155mm M107". Archived from the original on 7 March 2007.
- "1943 Steel Cent | Lincoln Steel Penny". Retrieved 2019-04-23.
- Untracht, p. 49–50
- Untracht, p. 246