Backup pad designed to support 3M™ Roloc™ 3 inch diameter abrasive discs. This pad has a 1/4-20 INT thread which allows it to be mounted directly to tools with 1/4-20 EXT threaded shafts or use with Roloc™ shank to fit collet chuck tools. Rubber back-up pad supports 3M™ Roloc™ abrasive discs in different degrees of hardness for varying grinding applications. Conveniently mounts<br />directly to tools with threaded shafts or used with Roloc™ shank to fit collet chuck tools. - Hard Density Rating - 20,000 Max RPM - Disc attachment is quick and easy, increasing productivity - Versatile system works with drills, disc sanders, right angle grinders, and rotary sanders