Abstract: An abrasive disc mounting assembly for attaching an abrasive disc to a rotary motor drive. The assembly includes a backing pad with a front face and a rear surface. A tapered recess is formed in the front face and extends into the backing pad, the recess having a flat base at its inward end. A hole is formed in the recess and extends through the backing pad from the base to the rear surface. The hole is centered within the recess. A grinder spindle is sized to fit within the hole. The spindle has threads formed on one end. The assembly also includes a nut with a shape that is complementary to the shape of the recess so that the nut seats within the recess. The recess and nut include anti-rotational features that prevent one from rotating relative to the other as the nut seats within the recess.

Abstract: An abrasive disc mounting assembly for attaching an abrasive disc to a rotary motor drive. The assembly includes a backing pad with a front face and a rear surface. A tapered recess is formed in the front face and extends into the backing pad, the recess having a flat base at its inward end. A hole is formed in the recess and extends through the backing pad from the base to the rear surface. The hole is centered within the recess. A grinder spindle is sized to fit within the hole. The spindle has threads formed on one end. The assembly also includes a nut with a shape that is complementary to the shape of the recess so that the nut seats within the recess. The recess and nut include anti-rotational features that prevent one from rotating relative to the other as the nut seats within the recess.