Dynamic die misalignments sometimes caught in mid-drift
- Published: Jun 15, 2012, 8 PM
Coinage presses are rugged machines designed to remain stable in face of murderous, incessant pounding. But these stresses can occasionally knock loose a die or die assembly so that it drifts to one side, creating a horizontal misalignment. Human error also plays a role in creating these mishaps, as when a die (or die assembly) is not properly installed, locked down or maintained.
Major horizontal misalignments almost always affect the hammer die. Since it is not confined by the collar, the hammer die can drift unimpeded. Horizontal misalignments can be stable or dynamic.
Evidence for rapid, dramatic lateral die shifts is abundant and diverse. It includes:
(1) Coins with multiple sets of staggered, misaligned clash marks.
(2) Series of coins struck by the same die pair with different amounts of misalignment.
(3) Misaligned die errors with misaligned clash marks in a different position.
(4) Machine doubling (any of three types) featuring a dramatic lateral shift.
(5) Coins with a misalignment in one direction and strong machine doubling pointing in the opposite direction.
(6) Coins with a design ablation error at one pole and slide doubling (a form of machine doubling) travelling in the opposite direction.
(7) “One-sided” multi-strikes involving a centered first strike and a strongly misaligned second strike.
Most misaligned die errors are devoid of clash marks. And staggered clash marks usually appear on coins that are otherwise unremarkable. The 1983-P Jefferson 5-cent coin illustrated on this page shows two sets of clash marks that are widely separated from each other. The obverse (hammer) die was misaligned toward the left when the second clash occurred. However, by the time this coin was struck, the hammer die had returned to the centered position. A press operator may have restored the die to its normal position or it could have returned to center spontaneously.
It is therefore a welcome event when a misaligned die error co-occurs with a set of staggered clash marks. Such errors essentially capture the hammer die in mid-drift.
The illustrated 1974-D Jefferson 5-cent coin shows a roughly 8 percent horizontal misalignment toward the 3:00 position. It also has three sets of clash marks moving in the same direction. The set of clash marks farthest to the right on the obverse face (and farthest to the left on the reverse face) records a position for the obverse die that matches its placement when it struck this coin.
An even more dramatic case of “motion capture” is seen on a 1998 Lincoln cent. Here there is an approximate 10 percent horizontal misalignment of the obverse die toward the northwest. On both sides of Lincoln’s bust one can count at least five sets of staggered clash marks steadily moving toward the southeast. The reverse also shows multiple, staggered clash marks, although they’re not as clear as the “pillars” on the obverse.
It’s very clear what happened to this coin. A series of collisions took place, with the obverse die moving progressively farther toward the northwest after each collision. The clash marks are too closely-bunched and overlapping to be sure if the ones located farthest toward the southeast precisely match up with the present position of the obverse die. But they’re undoubtedly somewhere in the vicinity.
Multiple, staggered clash marks (sometimes called “chatter clash”) are not all that uncommon, although the amount of movement demonstrated in this example is quite unusual. Both this and the previous example nicely illustrate the progressive nature of some major horizontal misalignments. Other major horizontal misalignments of equal or greater magnitude develop instantaneously.
I have encountered four cents struck by the die pair described last. All show the same amount of misalignment in the strike. This would seem to show that, once the die reached this position, it stopped moving around, at least for awhile.
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