Coated abrasive disc

Claim 1

A one-piece coated abrasive grinding assembly for mounting on a shaft to be rotated by a power tool, the grinding assembly having an abrasive grinding face for grinding a workpiece surface and having a periphery useful for grinding a groove in a workpiece, the grinding assembly comprising: (a) a disc made of thermoplastic material and having a thickened hub portion for receiving said shaft and having an integral flexible workpiece-contour-following disc portion disposed normal to the hub portion and extending to the periphery of the disc, the diameter of the flexible disc portion being great as compared with its thickness; (b) a layer of thermosetting plastic resin which contains abrasive grit coated directly on the workpiece-contour-following disc portion which comprises said grinding face, the plastic resin being compatible with the thermoplastic material of the disc portion and being bonded and adhesively fused thereto; and (c) the thermoplastic disc material being smoothly and continuously heat-disintegrated at the same rate as the plastic resin grit-containing layer is abraded away when the periphery of the disc portion is used for edge grinding a workpiece, whereby to present fresh grinding grit to the workpiece as the diameter of the disc portion decreases.