PART VI. Striking Errors:

Edge strikes

Definition: A planchet or coin that is struck on-edge.

Edge strikes occur when a planchet or a previously-struck coin is positioned on edge when the dies come together. The disc may enter the striking chamber spinning on its edge or rolling on its edge. It may be kicked up into a vertical position by the feeder/ejector or a neighboring planchet or coin that occupies the striking chamber at the same time. It might be caught on edge by the descending hammer die as the disc flies across the striking chamber.

In all cases, the disc is not quite vertical when struck. If it were, it would be transformed into a foldover strike.

This is a prototypical edge strike. The coin was kicked out of the striking chamber as it bent beneath the impact of the dies The two poles carry die-struck design elements while the unstruck area between them has buckled.

Other edge strikes can take on a very different appearance. In some cases, the coin falls on its side within the striking chamber in a centered, slightly uncentered, or visibly off-center position and receives a follow-up strike as the hammer die completes its downstroke. In other cases, one or both poles bend, or the metal is dragged over onto one of the adjacent faces, so that a “paraxial foldover flap” appears at one or both poles.