1974 (D) Lincoln Memorial Cent - CU-1C-1974D-09 Cud

Description

CU-1C-1974D-09 is a cud on the 1974-D Lincoln Memorial cent. The mechanism behind each cud is fundamentally the same: repetitive high-pressure striking cycles induce fatigue in the die steel, particularly at the rim where geometric stress concentrations exist at the interface between the design and the collar. Over time, a crack nucleates at one of these stress points, propagates through the die steel, and eventually liberates a fragment of the rim. Once the fragment separates, every subsequent strike produces a coin bearing the cud — a raised, featureless mass of metal at the rim where the die material is absent. CU-1C-1974D-09 adds another data point to the circumferential map of rim failures on 1974-D dies, and its specific position distinguishes it from the preceding eight entries and the four that follow. The Denver Mint's quality control procedures during this era would have eventually detected the rim damage and pulled the affected die from service, but the delay between failure onset and detection — which could span thousands of striking cycles at production speed — created a population of CU-1C-1974D-09 specimens that entered circulation.

Cross References

• CU-1C-1974D-09

External References