Cud Coin Errors: Raised Rim Breaks From Die Failure

A cud error is a raised, featureless lump of metal at the rim of a coin, created when a piece of the coin die breaks away completely. The void left by the missing die fragment fills with metal during striking, forming a distinctive raised blob. Cud collectors catalog these by die position, size, and the coin series they appear on.

What This Means

Cuds represent the final stage of die deterioration at the rim. When stress fractures near the rim progress until a piece of die steel breaks free, the resulting void fills with coin metal during striking. True cuds always touch the rim — interior raised areas from die breaks are classified differently.

What to Look For

• Raised, shapeless blob at the coin's rim
• Featureless surface on the raised area — no design detail
• The cud is integral to the coin, not attached separately
• May appear on obverse or reverse
• Size ranges from tiny rim bumps to large blobs covering several millimeters

Common Mistakes to Avoid

• Calling interior die breaks "cuds" — true cuds extend to the rim
• Confusing struck-through debris with cuds
• Not examining the full rim of every coin during searches
• Assuming cuds always cover letters — they can be in any rim position
• Overlooking small cuds that are easy to mistake for rim bumps

What Affects Value

Cud values depend primarily on size (larger cuds are scarcer and more dramatic), location (cuds obscuring design elements are more interesting), denomination, and date. Well-known die-specific cuds may have dedicated collector followings.