The file belt CS 310 XF by Kingsport has been designed especially for use in combination with hand tool belt grinders. When used on metal, the product is best used for the precision sanding of radii and contours. The abrasive comes with a cotton backing. This backing is exceptionally flexible, yet tear-resistant. Combined with the strong grain adhesion, the backing provides for consistently high quality sanding results and a long service life. The butt joint of these flexible belts makes them the abrasive of choice for hand tool belt grinders. A fabric-reinforced film on the joint ensures that the bond remains perfectly strong.