What Are Doubled Die Coins and How to Identify Them

Doubled Die Coins Are Not Double Struck

1955 Doubled Die Obverse Lincoln Cent
1955 Doubled Die Obverse Lincoln Cent James Bucki

Many people confuse double die coins with double struck coins. The significant difference is that double-struck coins are hit twice by the same coin die during the striking process. A doubled die coin is produced when the coin die is not manufactured correctly. This manufacturing error leads to the appearance of two images on a single coin die. The more obvious and distinct the error is, the more the coin will be worth.

Doubled Die Coins

The coin die that strikes double die coins has a partial or fully doubled image. Therefore, the coin has two identical images that are slightly offset. The doubling occurs from mistakes in the die hubbing process. This results in a coin die having more than one image on it.

1955 doubled die Lincoln Cents (see photo) are the classic example of a doubled die. These double died coins sparked the start of the error coin collecting hobby in the United States. Although no other doubled die types exhibit the remarkable degree of doubling seen on the 1955 Lincoln cent, additional cents have emerged from the U.S. Mint. Other noteworthy doubled die coins are the 1972 and 1995 Lincoln Cents.

1972 Lincoln doubled die obverse.
1972 Lincoln cent with doubled die obverse.

Heritage Auctions, HA.com

Not Double Struck

Many people mistake double-struck coins for doubled die coins. The critical difference is that double-struck coins are struck more than once while the coin is in the coining chamber of the coining press. When this happens, the first impression is flattened or sometimes obliterated by the second strike. Subsequent strikes will also flatten or obliterate the design from earlier strikes.

Coin dies that are not appropriately made result in doubled die coins. As indicated above, it takes several impressions from the coin hub to make a coin die. If the mint employee does not align the coin hub perfectly above the coin die, a second impression will result in a slightly off-center coin die from the first. If this coin die is used to make coins, all coins made from the die will have this doubling effect.

1945 asked double struck walking Liberty half dollar
A double struck coin  Heritage Auctions

Doubled Die Designations

Coin collectors and numismatists will examine the coin and indicate if the doubling is on the obverse or the reverse. Some doubling effect is so minute that it requires a loupe or microscope to see it. When cataloging coins, coin collectors and numismatists will designate Double Die Obverse with the letters "DDO." Double Die Reverse coins will carry the "DDR" designation.

More pronounced doubling, such as the 1916 Indian Head Doubled Die Obverse, command a premium when they come to market. It is very obvious that only the date is doubled while the rest of the design is not.

1916 Buffalo Nickel Doubled Die Variety
1916 Buffalo Nickel Doubled Die Variety

Heritage Auction Galleries, Ha.com

Tripled, Quadrupled, and More

Since producing a coin die involves multiple impressions from the coin hub, the die may need more than two impressions. If the mint worker does not align the coin hub precisely with the coin die, it is possible to produce a Tripled Die or a Quadrupled Die. These are designated as follows:

  • TDO: Tripled Die Obverse
  • TDR: Tripled Die Reverse
  • QDO: Quadrupled Die Obverse
  • QDR: Quadrupled Die Reverse

Beware of Chinese Counterfeits and Machine Doubled Coins

Chinese counterfeiters are manufacturing some of the more valuable doubled die coins (1955 and 1972 Lincoln pennies). These are high-quality coins made by counterfeit manufacturers in China. Unfortunately, it is not against the law in China to make "reproductions" of United States coins. Therefore, before you buy one of these high-priced coins, you should make sure that you are buying it from a reputable coin dealer or purchase a coin certified by a third-party grading service.

A second confusing aspect of doubled die coins is that some people confuse them with machine doubled coins. This error type is also known as Mechanical Doubling or Die Abrasion Doubling. These coins are technically considered mint errors, but they are not collectible and are only worth face value.

The proper numismatic term is "doubled die." Sometimes people refer to these as "double die." Although this is incorrect, most coin dealers will know that you are referring to doubled die coins.

Edited by James Bucki