Part VII. Post-Strike Mint Modifications:

Edge Lettering Applied After Strike:

Lettering Die Inclusion

Definition: Foreign matter that is forced into the edge of a manganese-brass clad dollar coin by the lettering die.  Such errors may be difficult to distinguish from foreign matter forced into the edge of a planchet during the upsetting process.  The main difference is that a lettering die inclusion will protrude from the coin’s edge while an upset mill inclusion will be flush with the edge.

This 2007-P Jefferson dollar has a spiral metal shaving embedded in its edge.  Strongly attracted to a magnet, it’s probably composed of steel.  The right arm of the U of PLURIBUS is deeply impressed into the metal shaving because of the latter’s tight fit against the lettering die.  Discovered by Troy Shoopman.