Standard Abrasives Quick Change P.A.R.T. Disc Mandrel secures the Standard Abrasives Quick Change P.A.R.T. Disc to a rotary tool with a 5/8-inch collet assembly. These P.A.R.T. (Paint Anodized Removal Tool) Discs are used to clean and prep painted or corroded surfaces around holes prior to re-riveting or connecting a ground wire.