Pennies in the United States have been made of different materials throughout history, but the current composition since 1982 is primarily zinc with a thin copper plating. Specifically, modern pennies are composed of about 97.5% zinc and 2.5% copper plating. This change was made due to the rising cost of copper, making it more economical to produce pennies with a zinc core coated in copper
. Historically, pennies were made of nearly 100% copper before 1857. Between 1864 and 1982, they were mostly made of bronze, an alloy of about 95% copper and 5% tin and zinc. During World War II, in 1943, pennies were made of zinc- coated steel to conserve copper for the war effort. After the war, the composition returned to mostly copper alloys until the switch to copper-plated zinc in 1982
Summary of Penny Composition Over Time:
- Before 1857: Nearly 100% copper
- 1864–1942: Bronze (95% copper, 5% tin and zinc)
- 1943: Zinc-coated steel (wartime measure)
- 1944–1982: Mostly bronze or gilding metal (95% copper, 5% zinc)
- 1982–Present: Copper-plated zinc (97.5% zinc core, 2.5% copper plating)
Thus, today's pennies are mostly zinc inside with a thin copper coating on the outside to maintain their traditional appearance
