1 inch hole optimizes mounting of 6 inch bristle discs on bench motors with a 1 inch diameter shaft
3M Telescoping Wheel Flange Adapter (Part No. 5, sold separately) can be inserted in the center hole to adapt to shaft sizes as small as 1/2 inch diameter
Can be used with one or more 3M Spindle Extender Adapters (Part No. 30134, sold separately) when additional layers of bristle discs are required
Two-piece flange adapter holds a minimum of 7 bristle discs