A coin’s strike or the amount of detail brought up from the strike is a vital consideration when grading a coin. It is heavily considered in market grading, but it is not as much a consideration in technical grading.

Weakly stuck coins may not have been the result of poor quality but were a result of an attempt to extend the life of the dies. If a branch mint did not receive enough dies from the Philadelphia Mint, where the dies were produced, they may have resorted to striking coins at a lower pressure to allow for producing coins throughout the year. Since weakly struck coins erode dies at a slower rate the decreased striking pressure lowers friction between the die and the planchet, which allows for producing more coins with the same die.  

It can be difficult to determine the difference between a weak strike and wear on a coin. Weakly struck coins exhibit loss of detail on their high points. Detail will also be lost where the cavity between the dies is the greatest during striking. Wear, on the other hand, almost always occurs first on a coin’s high point.  

When a coin is weakly struck the area of the planchet that does not meet the die retains the original characteristics of the planchet. A coin may retain the scratches and dents from the original planchet.  The defects in the planchet may result in the coin receiving a lower grade.

Over polishing of the dies can also result in a weak strike. To understand the effect of over-polishing the dies you must realize that the lower areas on the coin are the highest areas on the dies. There will be a loss of detail on the coin and the area will have a different texture and appearance. This is because that area of the coin receives little or no impression from the dies. It will lack flow lines and luster. Over-polishing of these areas may also produce a “lake-like” effect on the coin, which appears as a flat area on the coin.

You will find many coins that have weak strikes. The Morgan Dollars from the New Orleans Mint, the High Relief Peace Dollar of 1921, the Walking Liberty Half Dollars of the early 1940s from the San Francisco Mint and a number of years in the Indian Head nickel series.