SKH-1c-1971S-01 Spike Head

Description

First spiked head variety documented for the 1971-S proof Lincoln Memorial cent, SKH-1c-1971S-01 records a die crack originating at Lincoln's head on a San Francisco proof die — a type of failure more commonly associated with high-volume business strike dies but occasionally occurring on proof dies as well. Cataloged by Cuds on Coins with a documentation note dated September 14, 2018, this variety carries no cross-references to other attribution systems. The spiked head phenomenon results from a fatigue crack developing at the high-relief contour of Lincoln's portrait, where the intricate hair detail creates stress risers in the die steel that serve as initiation sites for crack propagation. As the crack opens during continued use, it forms a narrow channel that fills with planchet metal during each strike, producing a raised spike extending from Lincoln's head into the surrounding obverse field. On a proof die, the development of a spiked head represents a notable event because proof dies are typically retired earlier in their service life than business strike dies, reducing the opportunity for fatigue cracks to nucleate and grow. The fact that SKH-1c-1971S-01 developed on a proof die suggests either that the die remained in service long enough to accumulate sufficient stress cycles or that the die carried a pre-existing metallurgical weakness at the crack initiation site. Proof striking preserved the spiked head with mirror-field clarity — the raised spike contrasting sharply against the reflective proof surface in a way that makes it more visually prominent than comparable spikes on business strike cents, where the surrounding lustre patterns can partially mask the crack-filled projection.

Attribution History

• Discovered by Jim Ussery
• Cross reference: none. 09/14/2018.
• Expert attribution by Cuds on Coins

External References