1964PR-1DER-002T Trail Die Reverse

Description

Cataloged as the second proof trail die reverse for the 1964 Lincoln cent, 1964PR-1DER-002T confirms that the trail mark phenomenon documented in the landmark 1964PR-1DER-001T discovery was not a one-time occurrence on proof reverse dies. Trail dies exhibit fine parallel lines radiating from design elements, created during the hubbing process when metal flows under extreme pressure as the hub is pressed into the softened die blank. These trail marks record the physical displacement of die steel during the moment of hub-to-die contact, preserving a snapshot of the metal flow dynamics at the instant of die formation. On the Lincoln Memorial cent reverse, trail marks typically appear on the letter elements of UNITED STATES OF AMERICA, E PLURIBUS UNUM, or ONE CENT, as the raised portions of the hub create the highest-pressure contact points where metal displacement is most pronounced. The identification of a second proof reverse trail die for 1964 strengthens the evidence that proof die manufacturing at the Philadelphia Mint in that year created conditions conducive to trail mark formation on both obverse and reverse dies. Attributed by Trail Dies as catalog number 1964PR-1DER-002T. The 1964 proof cent mintage of 3,950,762 pieces was the last proof production at the Philadelphia Mint before the 1965-67 suspension, after which proof coining moved to the San Francisco Mint. Proof dies served approximately 3,000 impressions before being retired, placing a ceiling on the surviving population of this trail die variety. Struck on a polished 3.11-gram, 19mm bronze planchet of 95% copper and 5% tin-zinc.

Attribution History

• Discovered by Bob Piazza
• Expert attribution by Trail Dies

External References