CU-1C-1985-16 Cud

Description

Planchet feeding mechanics and die alignment contribute to the forces that generate cuds, and CU-1C-1985-16 on the 1985 Philadelphia Lincoln Memorial cent was produced within a high-speed coining press environment where these mechanical factors operated continuously. Modern coining presses at the Philadelphia Mint in 1985 operated at rates exceeding 600 strikes per minute, with planchets fed automatically from hoppers through feed tubes into the striking chamber. Each planchet had to arrive centered between the dies with correct orientation — when feeding mechanisms delivered planchets slightly off-center or at an angle, the resulting uneven striking load placed asymmetric stress on the die face. Repeated asymmetric loading concentrates stress at specific rim locations, accelerating crack formation in those areas. Die alignment — the precise parallelism between the obverse and reverse die faces — further influences stress distribution. Even minor misalignment measured in thousandths of an inch creates pressure differentials across the die face that compound over hundreds of thousands of strikes. These mechanical realities mean that the location of a cud on a given die is not random but reflects the specific stress pattern that die experienced during its service life. Struck on copper-plated zinc planchets at 2.5 grams and 19mm from the 1985 mintage of approximately 5.65 billion cents.

Attribution History

• Discovered by Joseph Klein
• CU-1C-1985-16
• Expert attribution by Cuds on Coins

External References