The composition of the U.S. cent has changed seven times in the past two centuries. The last copper-dominant pennies were issued in September of 1982.
Changes to the Penny Throughout the Years
The U.S. penny was last issued with a 100% copper composition in 1857. Nickel was added to the Flying Eagle penny in 1856 in hopes of increasing durability while also decreasing costs and 88% copper, 12% nickel pennies were in production until 1864. This composition is also known as nickel silver or German silver.
In 1864, the composition of the Indian Head penny changed to further reduce productions costs by incorporating a bronze planchet with 95% copper and the balance in tin and zinc. This composition was used until 1942.
While World War II was raging, copper was needed for airplanes, tanks, wiring, ammunition, and more. The 1943 steel penny was produced in zinc-coated steel to preserve copper for the efforts amid the war.
Following the end of World War II, pennies were issued in a composition of 95% copper and 5% zinc known as gilding metal.
In 1947, the cent composition changed back to bronze with a 95% copper and 5% tin and zinc composition. Zinc was re-introduced to the penny in hopes of adding greater durability. In 1962, the penny returned to the gilding metal composition, which was issued until 1982 when the final 95% copper pennies were minted.
Pennies in the 1970s
The price of copper rose in the 1970s to the extent that pennies almost contained their face value in copper. To alleviate the high seigniorage and concerns about the potential for hoarding, the U.S. Mint tested alternative metals like bronze-clad steel and aluminum to replace the 95% copper cent.
The Mint settled on a 95% aluminum coin and more than 1.5 million 1974 aluminum pennies were struck before the composition was rejected by Congress amidst loud opposition. While the 1974 aluminum cents were recalled, there are some that did not return to the Mint and could be exceptionally valuable if found. Copper prices began declining in late 1974 as did the cost to produce a penny, and the composition was not changed again until 1982, when copper prices began rising once more.
October of 1982 saw the penny change once more, this time to a 95% zinc, 5% copper planchet. Excluding the 2009 bicentennial collector’s pennies, all United States cents have been issued in copper-plated zinc.
How to Tell 1982 Pennies Apart
Distinguishing the 1982 copper penny from the zinc penny can be done by either weighing them, flipping them, or letting them fall to the surface of a table. Weighing them, 95% zinc pennies weigh 2.5 grams and 95% copper pennies composed of gilding metal issued until September 1982 weigh 3.11 grams.
The zinc-dominant pennies make a lower clunk sound when they fall to a hard surface and produce no sound when they are flipped in the air. Meanwhile, copper-dominant pennies make a noticeably high-pitched sound when they fall to a tabletop and produce a ringing sound when they are flipped in the air.
Is There a Difference Between Pennies and Cents?
The official name for the smallest denomination of U.S. coin is the cent, although the colloquial name, penny, is often used instead. While the terms penny and cent are used interchangeably in the U.S., the word penny carried a different meaning in the United Kingdom until the early 1970s.
In 1971, the United Kingdom began using the decimal currency system. The value of a British penny had been 1/240th the value of a pound but today, it is worth 1/100th the value of a British pound now.