The flat rim $20s are much scarcer than the wire rim Saints, the latter having been caused unintentionally by -- loose retaining collar and the multiple, high-tonnage blows to bring up the design on each of these coins. While flat rim $20s are not necessarily rare, they are certainly much scarcer than their wire rim counterparts. Beware when buying flat rim $20s that they are not misrepresented wire rims. While many circulated wire rim Saints may appear to have flat rims, bona fide flat rim pieces have raised lines on the flattish edge running parallel to the rim.