This rigid 8” tubular rasp with 100µ diamond abrasive (roughly 100#) on one side and 25µ (800#) on the other is a perfect tool for sharpening hard steel tools. I use it like a file (but a file skates on hard steels), sliding the tube over the stationary edge. I have sharpened my Ames grass cutter blades, a Wilkinson bypass pruner, and a cleaver. I have good control of the sharpening angle by adjusting the edge to the angle and holding the rasp horizontally. This tool is more practical than holding a 1 x 6 inch plate. Sharpening is satisfying, but using a sharp tool is a thrill!