This diamond sharpener’s unusual curved shape is perfect for getting at complex curves or angles, like spurs on auger or brad point drills, or into the serrations on knives. Works beautifully whenever you need to re-sharpen or touch up a concave surface or small, difficult-to-get-at place on a tool or drill bit. Our customers tell us that this serves as a useful hack for many jobs beyond sharpening, and that it’s a “must-have tool for mechanics and handymen.” One customer writes: “Its tapered shape makes it useful for reaming out small ports in an engine and filing burrs in places normally unreachable. I can think of numerous, past jobs where this would have made life easier.”

Although the need may be sporadic, when it arises you’ll want one of these around. The silver lining is that it is really inexpensive, so we recommend every shop should have one of these in a drawer. Buy a pair, and keep one in the kitchen drawer or your vehicle.