Abstract: A cover for a rotary anvil which includes in combination, a main body of flexible material having ends with alternating lugs and recesses adapted to interlock with one another, and a comparatively inelastic reinforcing sheet of metal or the like attached to the inner surface of the main body and having ends adapted to meet or overlap when the ends of the main body are interlocked, one end of the reinforcing sheet protruding from the lugs of its associated main body end so that the meeting of the reinforcing sheet ends does not coincide with the interlocking surfaces of the lugs and recesses. A shim member may be provided on the inner surface of the reinforcing sheet and extending circumferentially a sufficient distance to underlie the interlocking surfaces of the lugs and recesses to there raise the cutting surface of the cover.