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.
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.
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.
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Scan Your Coin NowA cud is a raised, featureless blob of metal at the rim of a coin, caused by a piece of the coin die breaking away. The void in the die fills with metal during striking, creating the raised area.
Cuds range from small rim bumps to large blobs that can cover 10-20% or more of the coin's face. Larger cuds are significantly scarcer and more collectible.
Cuds are one of the easier errors to spot because the raised blob is visible to the naked eye. However, they are not extremely common — most dies are retired before developing full cuds.
A die crack is a raised line from a fracture in the die — no metal is missing. A cud occurs when a piece of die at the rim actually breaks away, leaving a void that fills with metal to create a raised blob.