RIDB-1c-1964-01 Retained Interior Die Break

Description

Documenting a retained interior die break on a 1964 Philadelphia-minted Lincoln cent, this RIDB-1c-1964-01 represents a distinctive category of die failure that differs fundamentally from both cuds and full interior die breaks. A retained interior die break occurs when a piece of the die fractures away from the interior of the die face — not at the rim, which would make it a cud — but remains held in position rather than falling out of the press entirely, which would create a full interior die break (leaving a featureless raised area on the coin). Because the broken piece stays in place, the design detail is largely preserved in the affected area, but a network of raised die crack lines surrounds the retained fragment, marking the boundaries of the fracture. On this variety, the die cracks appear on Lincoln's forehead, described as "white arrows" in the reference photographs, outlining the perimeter of the retained die fragment. The forehead location is significant because it represents a relatively flat, unsupported area of the die interior where stress concentrations can develop during repeated high-pressure striking. The 1964 Philadelphia Mint produced 2,648,575,000 business strike cents, pushing dies through extended service that increased the cumulative stress on the die steel. Cross-referenced with date 04/15/2019 and attributed by Cuds on Coins. A companion listing exists under the same RIDB-1c-1964-01 designation classified as a "Cud" error type on a proof strike. Struck at the Philadelphia Mint on a 95% copper, 5% tin-zinc planchet weighing 3.11 grams at 19mm diameter.

Attribution History

• Discovered by Pete Apple
• Cross reference number: none. 04/15/2019.
• Expert attribution by Cuds on Coins

External References