1964 Variety WMDO-001

Description

Among the most fundamentally important varieties in the entire 1964 Lincoln cent catalog, WMDO-001 is a Master Die Doubling Obverse — a category that is mechanically and conceptually distinct from the far more common working die doubled dies (WDDOs). In the U.S. Mint's die manufacturing hierarchy, a master hub creates a master die, which in turn produces working hubs, which then create the individual working dies that actually strike coins. A doubled master die means the doubling was introduced at the master die level: when the master hub was pressed into the master die blank, a misalignment between successive impressions embedded a doubled image in the master die steel. Because every working hub produced from that master die inherits the doubling, and every working die produced from those working hubs inherits it again, the doubling propagates across potentially hundreds or thousands of working dies rather than being confined to a single die as with a standard WDDO. This means that master die doubling can appear on an enormous number of struck coins — potentially millions — across the entire production run that used working dies derived from that master. The practical consequence for collectors is that WMDO-001 is far more common than any individual WDDO variety, since the doubling was replicated across the entire die family tree. However, master die doubling is typically very subtle, as any significant misalignment at the master die stage would have been caught during quality control before the die entered production. The cross-reference notation lists this as Wexler Variety ID: 1964 50¢ Pr WMDO-001 — the "50¢" designation is a data import artifact and does not indicate a half dollar; this is confirmed as a Lincoln cent variety. Attributed by the Wexler Team. Struck at the Philadelphia Mint from the 1964 production of 2,648,575,000 business strikes on a 95% copper, 5% tin-zinc planchet weighing 3.11 grams at 19mm diameter.

Attribution History

• Wexler Variety ID: 1964 50¢ Pr WMDO-001
• Expert attribution by Wexler Team

External References