3M™ Disc Retainer Nut securely fastens a fiber disc to a disc pad hub or face plate for use with a rotary power tool. This nut is made to fit 3M disc hubs and face plates, but also fits fiber disc holders from other manufacturers. After placing the disc pad hub, disc pad face plate, and fiber disc onto the tool, the final step to secure these items is to tighten the 3M™ Disc Retainer Nut. Use a 1-1/4 Inch spanner wrench with 1/4 Inch pins to tighten the disc retainer nut on the spindle. Most spanner wrenches provided with pneumatic or electric tools will fit 3M™ Disc Retainer Nuts.