Part VI. Striking Errors:

Intra-Strike Damage:

External Struck-Through Errors (With Cupping)

Cross-referenced as:

Part VI. Striking Errors:

Cupping:

On Unobstructed Strikes:

Forced:

By Foreign Object or Machine Part

Definition: The unstruck portion of an off-center planchet is forced down upon an underlying obstruction by the impact of the hammer die. This forces the unstruck portion of the coin upward and simultaneously leaves the underside of the unstruck crescent with an indentation which is called an external struck-through error.

This 2000-D Virginia quarter was struck off-center. The portion of the planchet that protruded outside the striking chamber rested on an obstruction. The impact of the hammer (reverse) die caused the presumed foreign object or machine part to push the unstruck crescent into a vertical orientation. It also generated a short arc of design rim. The external struck through error can be seen on the outside of the cupped portion of the unstruck crescent.

This off-center 2003 India 5 rupee coin features an external struck-through error and forced cupping generating by the foreign object or machine part that was positioned beneath the unstruck portion of the coin. The unstruck crescent is tilted upward at an angle of around 45 degrees. An arc of design rim formed along the base of the internal surface of the inclined metal.