A transitional error occurs when coins are struck on planchets from the wrong composition — typically when a planchet intended for the old composition is accidentally used after the Mint has switched to a new metal. The most famous transitional errors are 1943 copper pennies (should be steel) and 1944 steel pennies (should be copper). These errors occur at the boundaries when the Mint changes a denomination's metallic composition.
Throughout US minting history, several denominations have changed their metallic composition. Each change creates a brief window where leftover planchets from the old composition could be mixed with new-composition planchets. When an old-composition blank is accidentally struck with new-year dies (or vice versa), the result is a transitional error — a coin with the correct date and design but the wrong metal.
Transitional errors are among the most valuable error types because of their extreme rarity and historical significance. A genuine 1943 copper penny has sold for over $100,000. Even less famous transitional errors from composition changes in 1965 (silver to clad), 1982 (copper to zinc), and other years can be worth hundreds to thousands. Authentication is essential.
Upload a photo of your coin or currency and let ErrorHunt's AI scanner check for errors in seconds.
Scan NowThe 1943 copper penny — a Lincoln cent struck on a leftover bronze planchet when the Mint had switched to zinc-coated steel for that year due to wartime copper needs. Only about 20 are known to exist.
Major change years include 1943-1944 (penny steel/copper), 1964-1965 (dime, quarter, half dollar silver to clad), 1982 (penny copper to zinc core), and 2000 (Sacagawea dollar introduction).
Weigh it precisely. Transitional errors have the weight of the wrong composition. A 1943 copper penny weighs about 3.1g (vs 2.7g for steel). A 1965 silver quarter weighs about 6.25g (vs 5.67g for clad). Then seek professional authentication.
Yes. Copper-plating a 1943 steel penny is a common trick. Genuine transitional errors must be authenticated by a professional grading service. Weight, magnetism, and expert examination are all part of authentication.