Part VI. Striking Errors:

Struck-Through Errors:

Filled Collar / Obstructed Collar

Definition: It’s very seldom that a collar will accumulate dirt or debris, as it’s largely self-scouring.  Each time a newly-struck coin is ejected, it tends to carry with it anything that might have settled against the working face of the collar.  Nevertheless, once in a great while material will remain behind, lodged against the collar.

 As you might expect, reeded issues are the only ones in which this error type is known.  The grooves in the working face of the collar are more likely to accumulate foreign matter than are the smooth collars used for cents and nickels.

If the foreign matter rises no higher than the ridges on the working face of the collar, the edge of the affected coin will lack reeding for several arc degrees.  This portion of the edge won’t extend out as far as the normal, reeded edge.

If the foreign matter extends past the ridges on the working face of the collar, then this material will stand in the way of any planchet forced down upon it by the impact of the hammer die.  This collision will push coin metal upward from the edge and prolong it into a vertical flange.  The opposite face will show distortion of the rim in the form of a rounded shoulder.

At the moment, obstructed collar errors are known only from a few Canadian specimens.  Here we see the affected portion of a 1999 Canadian dime struck within an obstructed collar.  Coin metal has been scraped from the edge and forced into a vertical flange that is triangular in shape.  The corresponding area on the obverse face (struck by the anvil die) lacks the design rim and instead shows a rounded shoulder