Patent ID: 7001258

Claim:
A polishing jig for re-polishing a bearing including an inner ring, an outer ring and a roller for use in a back-up roll of a rolling mill including a shaft member on which an inner ring of a bearing for use in the back-up roll of the rolling mill is fitted; and a pressure-oil chamber operative in association with the feeding of pressure oil into said shaft member and which fixes an inner ring to a shaft member by protruding an outer circumferential part of said shaft member radially outwardly when the inner ring is fixed on the shaft member the polishing jig comprising an inner-ring fixing portion for axially fixing plural individual inner rings of a plurality of bearings fitted on said shaft member as axially arranged, wherein a plurality of pressure-oil chambers are formed internally of said shaft member corresponding to the plurality of bearings fixed on said shaft member and wherein re-polishing of an outside diameter surface of the outer ring of the bearing is performed by rotating the outer ring under the conditions that the shaft member is fixed to prevent the shaft member from rotating, and by polishing the outside diameter surface of the outer ring.