Submitted by JonSullivan on Fri, 05/29/2015 - 13:19


                                                                                                                                                                                                   by Jon P. Sullivan

There are a number of different types of double-strikes, some of which are very dramatic in appearance, while others are minor and only visible upon close examination. It’s an error type which is often found in concert with other error types, such as clips, die caps, and broadstrikes. The primary categories of double-strikes include: off-center double-strikes; flip-over, off-center double-strikes; double-strikes in-collar; and flip-over, double-strikes in-collar.

Off-center double-strikes are the most common type of double-strike, and are found on virtually every series of U.S. Coin. The error occurs when a planchet is fed into the collar and is struck into a coin, but then fails to be ejected properly by the feeder finger. It then rattles around in the striking chamber until it comes to rest off-center of the dies and is struck, resulting in a coin with a normal 1st strike, and a 2nd strike which is off-center.

The Susan B. Anthony Dollar shown above is a superb example of an off-center double-strike. It is a particularly nice example because the second strike is about 50% off-center of the 1st strike, which is the percentage off-center most sought after by collectors. Like many off-center double-strikes, the off-center strike has a uniface reverse. It is uniface because another planchet was already in the collar about to be struck, when this coin came to rest between the dies. The underlying planchet kept the reverse from being struck, although the obverse side of this coin was struck normally, since it was not obstructed by the planchet. It is always more desirable to have the off-center strike “normally” struck on both sides, as opposed to being “uniface” on one side as this coin is. It is actually much more common to have one side of the off-center strike uniface, than it is for the coin to be struck normally on both sides. Double-struck off-center coins, which are struck normally on both sides of the off-center portion, are often worth double the value of a comparative example which is uniface on one side!

Flip-over, off-center double-strikes occur in the same way that normal off-center double-strikes occur, except that the coin flipped over after it was ejected from between the dies. When the coin came between the dies, it was only partially centered between them, and so when it was struck, it was off-center. The resulting coin will have a normal 1st strike, but with an off-center 2nd strike, and showing the reverse side of the coin on the 1st strike’s obverse side. The 1998 Lincoln cent shown above is an example of this error type. The second strike is 80% off-center, with the obverse design visible on the 1st strike’s reverse. Flip-over, off-center double-strikes are much scarcer than normal off-center double-strikes, and are typically valued at more than double the value of a comparative off-center double-strike.

In-collar double-strikes occur when a planchet is fed into the collar and struck into a coin, and then is improperly ejected by the feeder finger, so that it rattles around in the striking chamber, before falling back into the collar and being struck again. A coin struck in this manner will virtually always show some degree of rotation between the strikes on the obverse and reverse, with the degree of rotation being completely random. An example of this error type is shown above.

An error type which is very rare for this series of coin, the 1937-D buffalo nickel shown is a rotated double-strike in-collar, and has a 70 degree clock-wise rotation between the strikes (viewed from the obverse). Traces of the 1st strike can be seen under the second strike, with traces of the Indian’s headdress still visible on the obverse. The reverse shows more detail, with a faint outline of the buffalo and traces of lettering still visible.

(photo courtesy of Mike Diamond)

Flip-over double-strikes in-collar occur in the same manner in which normal in-collar double-strikes occur, except that the struck coin flipped over after it was ejected from the collar, and when it fell back into the collar, it was upside-down, with the coin’s obverse facing the reverse die and the coin’s reverse facing the obverse die. When the coin is struck, it will show traces of the reverse on the obverse, and vice-versa. This error type is quite rare for all series of U.S. coins, although it is perhaps the most common on Lincoln cents.

The 1997 cent shown above is a flip-over double-strike in-collar, and shows faint traces of the Memorial Building on the coin’s obverse, and on the reverse there are traces of Lincoln’s profile.

There are other types of double-strikes as well, such as the double-struck broadstrike and the double-strike with both strikes off-center, as well as double-strikes in combination with other errors, such as clips or die cap strikes or split planchets. If you have any questions about this error type, write me at: