1977 Lincoln Memorial Cent - CU-1C-1977-08 Cud

Description

Numbered as the eighth entry in the 1977 Philadelphia cud census, CU-1C-1977-08 was documented by Cuds on Coins and records another instance of terminal die failure from this high-mintage year. The physics behind cud formation are straightforward: tool steel under cyclic loading develops fatigue cracks that propagate through the material until a section of the die rim separates. The geometry of the break — its clock-position relative to the design, its angular extent, and its depth — determines the visual character of the resulting error on each coin struck after the failure event. Some cuds are thin crescents along the rim; others are broad, irregularly shaped masses that obliterate significant portions of the legend or design. The 1977 Philadelphia cent was struck without a mint mark on planchets composed of 95% copper and 5% zinc, the standard alloy that had been in use since 1962 and would continue until the composition change to copper-plated zinc in 1982. Attribution by Cuds on Coins.

Cross References

• CU-1C-1977-08

External References