IDB-1c-1988-01 Interior Die Break

Description

Cataloged as IDB-1c-1988-01 on September 9, 2016, this is the first documented interior die break on the 1988 Philadelphia Lincoln Memorial cent. An interior die break differs from a cud in a critical way: while cuds occur at the rim where a die fragment separates entirely, interior die breaks happen within the design field, away from the rim edge. A section of the die fractures and the broken piece drops out of the die face, leaving an enclosed void surrounded by intact die surface on all sides. When a planchet is struck by a die carrying an interior die break, metal flows into the void and produces a raised, featureless island on the coin — a flat-topped plateau with no design detail, completely surrounded by normal design elements. This characteristic "island" appearance is the diagnostic hallmark that distinguishes interior die breaks from cuds (which always touch the rim) and from die chips (which are much smaller and involve surface flaking rather than deep fracture). Interior die breaks are less common than rim-connected cuds because the die's interior is generally more structurally sound than its rim, where the thinner cross-section and collar contact create additional stress. Struck on copper-plated zinc planchets (97.5% zinc, 2.5% copper) at 2.5 grams and 19mm.

Attribution History

• Cross reference: IDB-1c-1988-01. 09/09/2016.
• Expert attribution by Cuds on Coins

External References