US Coins

From The Memory Bank: Treasury moves to switch alloy

There was certainty in her voice when U.S. Treasurer Angela “Bay” Buchanan told Congress May 31, 1981, that the Treasury Department was “determined” to change the alloy content of the Lincoln cent, believed it had the authority to change it, and was planning to move full speed ahead.

Buchanan’s confidence stem-
med from the leeway Congress inserted into the law regarding cent alloy content in October 1974, when copper-mining and vending machine lobbyists convinced Congress to scuttle the Mint’s proposal to change the 95 percent copper cent to a 96 percent aluminum coin.

Metallurgical research

The Mint had undertaken research to replace the predominately copper cent in 1973 as the rising world price of copper began to push production costs near face value.

Congress, in its wisdom, decided it would take care of the issue in the future by authorizing the secretary of the Treasury to alter the ratio of copper to zinc in the cent “whenever the situation warranted in order to preserve and protect the issuance of United States coinage.”

Shortly after the 1974 skirmish, the price of copper dropped on the world markets and the Mint continued striking 95 percent copper cents. But as the world price of copper began to rise again in late 1979 and in early 1980, the U.S. Mint was ready. It had continued testing and had found a suitable alloy: 99.2 percent zinc with a 0.8 percent copper alloy for the planchet, with a plating of pure copper on the surface.

The most important factor in favor of changing to zinc was cost savings. Mint officials estimated that using zinc as the primary metal would save the Mint at least $50 million a year in production costs.

By the spring of 1981, copper, at 90 cents per pound, was again approaching the “danger zone.” At $1.12 per pound, the 95 percent copper cent would exceed face value to produce. With zinc at just 41 cents per pound, production costs could be almost halved.

However, one of the best arguments for changing was that, visually, most users would not notice the change.

Plating the coin with pure copper retained the outward appearance and color, giving it the greatest acceptance chance by a public that was portrayed by Mint officials as resistant to change.

Copper interests attack

Predictably, the copper industry mounted a multipronged attack. It went to court to challenge the Mint’s legal authority to change the alloy and also claimed that, if scratched, the zinc would corrode easily and cause the public to reject the coin. Public rejection, the experts said, would cause hoarding and lead to shortages, thus interrupting commerce.

At a March 31, 1981, House hearing, with test results in hand, Dr. Alan J. Goldman, the Mint’s assistant director for technology, calmly refuted every concern.

When copper industry experts railed that loss of contracts for the copper cent would economically wreck producers and manufacturers, Mint officials countered that the copper used in the 95 percent copper cent coin constituted only 1 percent of domestic copper production.

That’s all Rep. Frank D. Annunzio of Illinois, the Democrat chairman of the oversight coinage subcommittee conducting the hearing, needed to hear.

He publicly backed the Treasury’s proposal and Mint officials moved ahead with production in time to introduce the new zinc-copper plated cent with coins dated 1982.

Beth Deisher was editor of Coin World for 27 of the 31 years she was on the publication’s staff. She may be contacted at

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