A sanding device for use with a drill press having a drum divided diametrically into half sections. The drum is covered by a unitary layer of resilient rubber-like material such as neoprene. The cover hinges the drum halves together along one side of the drum. When an abrasive sheet has been installed on the device, the two halves are joined together by a nut threaded onto a short shaft which projects from each end of the drum. The upper nut has a metal shaft extending coaxially from the nut and this shaft can be used to attach the device to a drill press chuck or directly to a shaft. The mechanism for attaching the abrasive sheet includes two slots each of which extends from the diametrical surface of a respective half section. Each slot extends the length of the drum and is adapted to accommodate one end of the abrasive sheet. Preferably each slot extends radially outwardly from the center axis of the drum and is disposed at an angle less than 45 degrees with respect to a drum radius extending along the diametrical surface of the respective drum half away from the hinge formed by the cover.
A polishing apparatus for polishing a workpiece such as a semiconductor wafer to a flat mirror finish includes a rotary drum provided on a surface thereof with a polishing pad. A stand supports the workpiece to be polished. A controlling device controls reciprocation of the drum and rotation of the workpiece to obtain a relationship: in which V represents velocity of reciprocation of the drum reciprocating on the workpiece to polish an entire surface of the workpiece, .omega. represents rotational angular velocity of the workpiece, and L represents a distance from the rotational center of the workpiece to a radially outermost point on the workpiece.
