1991 (P) Lincoln Memorial Cent - SKH-1c-1991-18 Spiked Head

Description

Reported on July 1, 2024, SKH-1c-1991-18 of the 1991 Lincoln Memorial cent underscores a significant production management question: with 19 documented spiked heads — each representing a distinct die that developed a portrait-boundary crack — how many obverse dies did the Philadelphia Mint use for 1991 cent production, and what fraction of them cracked? Die replacement economics dictated Mint practice: manufacturing a new die involved a multi-step process of hub creation, annealing, hardening, and quality inspection, each consuming time, labor, and materials. Running a die past its optimal lifespan, even as minor cracks appeared, was economically rational if the resulting coins still met circulating quality standards. The 19 spiked heads demonstrate that the Mint clearly tolerated cracking at the portrait boundary on many dies rather than retiring them at the first sign of deterioration. This tolerance makes practical sense for a denomination produced in the billions — replacing every die that showed a hairline crack would have dramatically increased production costs for a coin whose face value barely covered its manufacturing expense. Struck at Philadelphia on copper-plated zinc planchets composed of 97.5% zinc and 2.5% copper, weighing 2.5 grams and measuring 19mm.

Cross References

• Cross reference: none. 07/01/2024.

External References