knife-rim 上市 Deposited
Thin raised extension of edge, at outermost rim of a coin, from where metal was forced between die and close collar at striking. Mint personnel call it a fin and object to its presence on coins because it can create problems in ejecting the finished coin. It is usually a cue to replace a collar which has stretched with prolonged use. Not diagnostic of proofs. Neither a flaw nor a specially desirable trait of a coin.
- Breen Encyclopedia