1955 double die

The 1955 doubled die is a minting error that occurred during production of the one cent coin at the United States Mint, in 1955. An error in the minting process caused a small (but notable) number of coins to be struck in such a manner that the year 1955 appears twice on the coin, with one "1955" slightly overlapping the other. Other parts of the lettering also show doubling.

The 1955 doubled die is one of the most famous error coins. It is well-known and collectible enough for genuine double die coins to fetch prices in the hundreds of dollars, depending on condition.

A similar error to the 1955 double die is the "poor man's double die." It is caused when the design of a worn die becomes eroded and distorted. It is much more common than the actual doubled die, and as such it sells for only a few dollars.