1967 Lincoln Memorial Cent - CU-1C-1967-04 Cud

Description

Cataloged as CU-1C-1967-04, this fourth cud variety for the 1967 Lincoln cent contributes to a body of evidence about die longevity and failure under the intense production conditions of the late 1960s. The mechanism of cud formation is rooted in the metallurgy of coin dies: working dies are manufactured from hardened tool steel capable of withstanding hundreds of thousands of high-pressure impressions, but each strike introduces microscopic damage at the grain boundaries of the steel. Over time, these micro-cracks coalesce and propagate, particularly at the die rim where the sharp transition from the die cavity to the collar wall creates a geometric stress concentration. When a rim crack reaches critical length, the affected fragment separates catastrophically, often during a normal striking cycle, and every subsequent coin struck by that die carries the cud as evidence of the failure. Cross-referenced as CU-1C-1967-04 and attributed by Cuds on Coins. Struck on a 3.11-gram, 19mm planchet of 95% copper and 5% zinc.

Cross References

• CU-1C-1967-04

External References