Part IV. Die Errors:

Hubbed-In Debris

Definition: When debris falls between the working hub and the considerably softer working die, the foreign matter is pressed into the latter.  When this foreign matter falls out, it leaves an incuse trace.  The foreign material will conform to the newly-formed recesses of the working die, as will its impression.  On the coin, the defect will appear as a raised imperfection that continues from the field to the design with no loss of clarity or relief.

This 1943 cent shows a thin ridge that extends from the design rim at 1:00 to a point near the base of Lincoln’s bust.  The ridge maintains a uniform thickness and relief until just before it fades out at its southern tip.  This ridge evidently represents the impression of a filament (metal or perhaps nylon) that was trapped between the working hub and the blank working die.  A few faint subsidiary ridges extend from the main ridge.  These may indicate that the filament was frayed.  Coin is courtesy of Robert Piazza.