3 Screw Mandrels Great For Grinding And Buffing Wheels. This is a new set of 3 screw mandrels. Great for grinding and buffing wheels. Each has a 1/8" (3 mm) shank and measures approximately 1 7/8" (47 mm) long. We work hard to update our descriptions and pictures of our merchandise. As part of a process of ongoing innovation by our suppliers, newer versions of the item shown may be shipped before we are able to complete an update. As a result there may be a slight variation in color and design.