PART III. Die Installation Errors:
Mules:
Two hammer dies / Foreign
Definition: Mules are coins struck by mismatched dies.
Note: Paired hammer dies are less often seen than paired anvil dies. This may be because the hammer die typically has a shorter neck than the anvil die and therefore cannot rise high enough inside the collar to bring a planchet within range of a descending hammer die. A die with a short neck will also have a problem ejecting a newly-struck coin.
The 1982 Jamaica cent shown below displays the reverse design on both faces. It’s likely that a hammer (reverse) die was retro-fitted to function as the anvil die by machining a longer neck into the shank. However, it should be noted that some presses are designed so that the hammer and anvil dies can be freely exchanged.
