The 15 x 15 in blocks of material in our Standard Abrasives™ unitized block - 600 series have a soft to medium density, making them a good match for medium-pressure cleaning and blending. The blocks are also effective for removing small burrs and radiusing edges and can be customized into various shapes for a range of uses. Standard Abrasives™ unitized block - 600 series comes in varying thicknesses that can be cut to size for hand finishing or refining. It is also ideal for specialty uses, when working with an intricate or unique workpiece that requires an unusual shape to achieve the desired result. After cutting and dressing the material into a customized shape, such as a mounted point or other abrasive specialty, attach it to a tool using a unitized wheel mandrel (sold separately). For your applications requiring a standard wheel shape, choose from the Standard Abrasives™ line of series 600 unitized wheels, offered with a center hole or quick-change attachment (sold separately). Standard Abrasives™ 7000047021, Series: 600, Aluminum Oxide Abrasive, Center Hole Attachment, 1/4 in Overall Thickness, Fine Grade