RRDC-10c-1940S-02 Bisecting Rim to Rim Die Crack

Description

Cataloged as RRDC-10c-1940S-02 by Cuds on Coins, this bisecting rim-to-rim die crack on the 1940-S Mercury dime traces a complete fracture path across the die from one rim point to another — the most structurally significant form of die crack because it divides the die face into two separate sections. Adolph A. Weinman's Mercury dime design (more properly the Winged Liberty Head), produced from 1916 through 1945, features Liberty wearing a winged Phrygian cap on the obverse and a fasces bound with an olive branch on the reverse. San Francisco struck approximately 21.56 million dimes in 1940, a moderate mintage that reflects the S-mint's role as the Pacific Coast production facility during the pre-war era. Bisecting die cracks represent an advanced stage of die failure: where a simple rim die crack runs from the rim partway into the design field and stops, and an interior break forms a closed island within the die, a bisecting crack traverses the entire diameter of the die from rim to rim, effectively splitting the working surface in two. The mechanical implications are substantial — the two halves of the die may shift slightly relative to each other during striking, producing coins where design elements on one side of the crack appear displaced or at a slightly different plane than those on the other side. The "02" suffix indicates this is the second documented bisecting rim-to-rim crack for the 1940-S dime, suggesting the die steel or production conditions for this mint-date combination were conducive to full-diameter fractures. Collectors should examine 1940-S Mercury dimes under 10x magnification for a raised line running completely across the coin from rim to rim, with possible subtle misalignment of design elements on either side of the crack.

Attribution History

• Discovered by Keith Christenson
• Expert attribution by Cuds on Coins

External References