2021 (P) Lincoln Shield Cent - SKH-1c-2021-11 Spiked Head

Description

Spiked heads provide authentic teachable moments for metallurgy education that extend beyond numismatics into materials science. SKH-1c-2021-11, as a cent struck from a cracked die, demonstrates in miniature the principles of fatigue fracture: a material subjected to repeated cyclic stress develops microscopic cracks that propagate under continued loading until they reach a critical size and the material fails. In a coining die, that failure manifests not as a sudden fracture of the entire die but as a progressive crack that eventually reaches the coin-contact surface and allows the struck metal to flow through. For instructors or museum educators, a spiked head cent is a tangible, inexpensive, and visually compelling specimen for illustrating fatigue crack propagation—a phenomenon that engineers study in bridges, aircraft components, and machine parts. The 2021 (P) Lincoln Shield Cent context simply adds numismatic relevance to what is fundamentally a materials science demonstration.

Cross References

• Cross reference: none. 01/27/2023.

External References