Errors where a previous year's planchet was used are some of the most exciting in all numismatics.
Numismatic Guaranty Corporation® (NGC®) is the world's leading authority on mint errors, a popular segment of numismatics. In Mint Error Coin Chronicles, we take an in-depth look at a mint error. This month's topic is Transitional Errors.
A Transitional Error occurs when a coin is struck on a planchet from a previous year with different metal composition. The most famous are the 1943 Lincoln Cents struck on 1942 bronze blanks. An example from the Partrick Collection graded NGC AU 55 BN is being offered this month in a Heritage Auctions sale. Only about 40 are known from all three mints, and they generally realize prices in the six figures.
To save copper for the war effort, the US Mint switched to zinc-coated steel planchets for 1943 cents. However, a few cents with the 1943 date were struck with leftover bronze planchets. It is likely that these bronze planchets remained lodged within tote bins that were later filled with steel planchets and then worked their way loose.
1943 Bronze Cent graded NGC AU 55 BN and
pedigreed to the Donald G. Partrick Collection
This same scenario is likely what led to a similar Transitional Error in 1944, when Mint facilities switched back to bronze planchets for the cent. A handful of examples of 1944 cents struck in San Francisco and Denver using the zinc-coated steel planchets are known to exist.
1944-D Cent graded NGC Mint Error 61 - Transitional
Not quite as easy to spot are the Transitional Errors that occurred with 1965 coins that were struck on the previous year's 90% silver planchets, instead of the new copper-nickel ones. An example is this 1965 Quarter graded NGC Mint Error AU 53 being offered in a Heritage Auctions sale this month. During 1965 and 1966, silver coins dated 1964 and clad coins dated 1965 were in production simultaneously.
1965 Quarter graded NGC Mint Error AU 53
There are also Transitional Errors struck on blanks intended for the next year. An example is 1964 coinage in clad instead of silver. More recently, transitional errors have been discovered involving the Susan B. Anthony and Sacagawea Dollars of 1999 and 2000.