Part VI. Striking Errors:

Uniface Strike:

Full Uniface Strike

Definition: Occurs when a planchet is perfectly centered over another planchet or coin and the two are struck together.  This error is also known as a full indent.

When an off-center planchet or coin is struck against an underlying planchet, this is known as an off-center uniface strike.

A full uniface strike can affect the face struck by the hammer die or the anvil die.  The coin can be struck in-collar or out-of-collar.

Above are photographs of a state quarter with an in-collar uniface strike.  Since state quarters were struck with conventional and inverted die setups, there’s no way to determine whether the die-struck obverse design was struck by the hammer die or the anvil die.

The coin depicted above is a cupped, uniface broadstrike.  It is what the companion of the previous coin would have looked like.  When two planchets are placed on top of each other and struck out-of-collar, the top coin curls up toward the hammer die, which in this case was the obverse die.  Because of its steeply upturned wall, coins like this are often mistaken for die caps.  But there is no convincing evidence that this coin was struck more than once.