Off-Center Strike

What it is

An off-center coin was struck when the planchet was not centered between the dies, so part of the design is missing and part of the blank shows.

What causes it

The planchet failed to seat properly in the collar before the dies came together.

How to identify it

• Part of the design is missing, with blank metal on one side.
• Collectors grade the error by percentage off-center: 5%, 50% and so on.
• Coins where the full date is still visible are more desirable.

How to tell it from damage

A coin that has been squeezed or hammered has distorted lettering. A true off-center strike has crisp, undistorted design on the struck portion.

What goes wrong in the feeding system

In a modern coin press, blank planchets drop from a hopper into a feed system that pushes each one into position over the lower die, inside the collar. Feed fingers carry the planchet in and then move the struck coin out. An off-center strike happens when a planchet lands partly on top of the collar instead of dropping into it, often because it was tilted, stuck by oil or jammed against the previous coin. The dies close anyway and strike only the part of the planchet that lies over the die face.

Because the planchet rests on the collar rather than inside it, every off-center coin is also struck out of collar. The struck portion spreads slightly with no wall to stop it. The unstruck portion keeps the round shape of the original blank and often its raised upset rim, the low rim pressed into the blank before striking.

The Mint uses sorting screens and inspection to catch misshapen coins, so many off-center strikes are destroyed before release, but some still escape. Most found today are cents, simply because cents have been struck in larger numbers than any other coin.

How off-center strikes are measured and described

Collectors describe off-center strikes by the share of the design that is missing, estimated by eye or with a transparent overlay. A coin under about 5% off-center may show only a thin crescent of blank metal and a missing piece of the rim. Coins from about 10% to 40% off-center show a clear blank area. The most popular range is roughly 40% to 60%, where the coin shows a bold crescent of blank metal yet keeps the date and most of the design.

Many attributors also record the direction using clock positions, noting where the blank area falls when the obverse is held upright. Coins struck more than about 80% off-center may show only a sliver of design and no date, which makes them hard to assign to a year. Collectors sometimes identify those by the design type and the alloy.

Related off-center errors

An off-center strike can combine with other errors. A double-struck coin may receive a normal first strike and an off-center second strike, leaving two overlapping designs. An off-center coin struck on a clipped planchet or a wrong planchet is a two-error combination. Indents happen when a second blank lies on top of the first during the strike, leaving a smooth, round depression and often pushing the coin off-center too.

Off-center strikes on coins struck in smaller numbers, such as half dollars, dollar coins, pre-1965 silver and gold, are much scarcer than off-center cents. Collectors who build sets by denomination often find the cent and nickel easy and the larger coins slow to complete.

Examining a suspected off-center coin step by step

Weigh the coin first. An off-center strike uses a full planchet, so it should weigh the same as a normal coin of its type within the Mint's tolerance. A coin that is noticeably lighter has probably been clipped, ground or altered.

Look at the blank area. It should be flat or show a gently raised upset rim at its outer edge, with the plain, slightly textured surface of an unstruck blank. Then study the boundary where the design ends. On a genuine off-center strike, the design stops cleanly at the edge of the die's imprint and lettering at the boundary is sharp, never crushed or smeared.

Finally check the edge. An off-center dime, quarter or half dollar has no reeding anywhere, because reeding is formed by the collar and the coin never entered it. The coin may also be slightly out of round because the struck part spread under pressure while the blank part did not.

Why damage cannot fake an off-center strike

Fake off-center coins are usually made by grinding away part of a normal coin or by hammering or squeezing one side flat. Grinding removes metal, so the coin is underweight and the blank area shows file or grinder marks. Hammering spreads metal unevenly and smears the design next to the flattened area instead of leaving a clean boundary. Neither method can produce a smooth, round unstruck portion with the original rim of the blank, because that surface was never touched by the dies.

Some fakes are struck with homemade dies on purchased blanks. They tend to have soft, grainy designs, incorrect weights and lettering that does not match genuine dies under magnification.

How off-center coins are graded

Grading services grade off-center strikes on the struck portion and note the error on the label, often with an approximate percentage. A sharp, lustrous example with a visible date ranks above a coin with the date missing. Combinations such as an off-center strike on a wrong planchet or an off-center second strike on a double-struck coin are scarcer still.

Frequently asked questions