Back to the original question in the thread:
The reason for the change from brass (not copper, exactly) to copper plated zinc is indeed because of the cost of copper. A composition change of the
Lincoln Cent first took place in 1943 when the bronze being used at the time was needed for the war effort. The result was disasterous.
After trying all sorts of metals, resin, cellulose, bakelite, plastic, and even wood, the Mint settled on steel plated in zinc. It was cheap and abundant. Problem is, they were minting steel coins with steel dies, which led to numerous problems with dies breaking, planchets rusting, and dies wearing out in odd ways well before they would have with the softer copper-based bronze.
In 1944, even though the copper was still needed for the war effort, the composition was changed back to bronze. A decision had to be made and they decided it was better to use the copper than go through the expense of continuing to produce cents made of steel.
In 1962 the tin was dropped from the composition of the cent, leaving the composition 95% copper, 5% zinc. Officially the 'bronze' cent had ended, and we went to a light alloy mixture of brass (which is copper and zinc, but usually more than 5% zinc).
In 1973 copper started to get too expensive to continue making cents, so they tested a few different compositions. A number of 1974 dated copper coated steel cents were made, but they decided against this and opted for aluminum. Early in 1974 some 250,000 aluminum cents were produced, then all but a handful were destroyed when the idea was nixed. They stayed with brass for the time being.
1982 was the year they finally went away from the brass alloy and tried copper plated zinc. It seemed to work well enough, so they stuck with it. 1982-1988 saw a large number of issues with the copper plating properly sticking to the zinc. They tried a number of different types of wash to prepare the zinc for the copper bath, and finally rested with something that worked somewhere around 1988 or 1989.
During 2002-2003 the price of copper had risen from $1.50 per pound to $4.25 per pound. Talk rose again of either changing the cent or eliminating it altogether. Obviously neither has happened to date, but two things have happened that will ultimately play a role in what happens in the future. A bill has been raised to change the composition of the cent to copper plated steel (again) and it seems to be going over. The other thing is that copper prices are way down from previous highs (mostly because of the construction bust). Copper is once again around $2 per pound.
So to sum it all up, there won't be regular changes in composition. The price of the metal isn't the only thing that goes into what the coins are made of, there are a lot of other things to consider too. And finally, the
Lincoln Cent has undergone more changes than any other U.S. coin. 41 different obverse designs, at least 20 different reverse designs, and 4 composition changes have happened - mostly under the radar of the typical onlooker, and even without notice by most collectors.
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Posted 12/13/2008 7:55 pm
