SKH-1c-1984-02 Spike Head

Description

Die stress analysis provides the framework for understanding why multiple spiked head varieties appear on a single date, and SKH-1c-1984-02 on the 1984 Philadelphia Lincoln Memorial cent is the second such fracture documented for this prolific year. The stress field surrounding Lincoln's portrait cavity is not uniform — it varies with the local geometry of the design, the die's hardness profile from heat treatment, and microscopic variations in the steel's grain structure. Each die develops its own unique vulnerability map, and the point where a crack initiates differs from die to die. SKH-02 cracked at a different location than SKH-01, producing a spike with its own distinctive direction, length, and character. The two varieties are readily distinguishable by comparing the spike's clock position relative to Lincoln's head and any associated die markers in the surrounding field. Cataloged with a documentation date of November 22, 2016 — just one day after SKH-01 — suggesting both varieties may have been submitted by the same searcher during a productive session. Struck on copper-plated zinc planchets at 2.5 grams from over 8.15 billion 1984-P cents.

Attribution History

• Discovered by Larry Peterson
• Cross reference: none. 11/22/2016.
• Expert attribution by Cuds on Coins

External References