Three Attachment Types: TS, TR, TP Standard Abrasives™ Quick Change Disc Pads come with one of three quick change attachment styles. Attachment styles include TS, TR and TP. TS is a standard metal-to-metal attachment style, TR is a 3M™ Roloc™ style nylon threaded male hub, and TP is a snap-on/snap-off nylon fastening hub. Each of the attachment styles allows easy swap out of discs with a speedy quarter turn. Choosing a Mandrel Our Standard Abrasives™ Quick Change Disc Pads are available with or without mandrels. Some TS and TR holder pads come with an attached 1/4-inch diameter TA4 mandrel. Others come with an attached 6 mm diameter TA6 mandrel. TP disc holders come with the TA4 mandrel attachment only. Disc pads are also available without mandrels, so users can select a mandrel of their choice for their application. Holders without an attached mandrel feature a 1/4-20 female thread interface for mandrel attachment. Once the mandrel is attached, users typically fasten the disc pad/mandrel assembly to a rotary tool or die grinder. Which Density is Best? Different densities signal varying levels of flexibility of the disc pad. Soft density disc pads are most flexible, and are typically reserved for fine grade abrasive products used in finishing and contouring applications. Medium density disc pads are typically used for general purpose type work. Hard density disc pads are the most rigid, and are typically reserved for coarse grade abrasive products used in weld grinding and stock removal applications. Altogether, Standard Abrasives™ Disc Pads allow for quick and easy disc attachment and removal, enhancing productivity and adding efficiency to your industrial applications. Quality Standard Abrasives™ Solutions for Industrial Applications The Standard Abrasives brand has supplied quality abrasives to the metalworking industry for over 50 years. Customers rely on our broad offering of high performance products including coated, bonded, and non-woven abrasive lines.