PART VI. Striking Errors:

Pile-ups:

Definition: This error type occurs when  a die cap is formed on the hammer die. However, the one difference in this case from other die caps is that after striking of the new coin the coin is not ejected, but it is bonded by the striking pressure to the die cap mass.

The images below show a multitude of 1996-P Lincoln cents that have been fused together. This particular error was caused by a die cap forming on the hammer die. As a planchet was feed into the striking chamber, the hammer die would make contact with the planchet and fuse it into the mass. This particular “pile-up” of coins is refereed to as a “pine cone” since it does resemble that object.