Abstract: A rotary grinder is mounted on a flat top bench to have a grinding wheel rotating on a horizontal axis. A blade holder for sharpening lawnmower blades has a slotted face bar pivotally mounted to a forward portion of a horizontal base plate resting on the bench top. A pair of upright legs extend upwardly from a rear portion of the base plate. A lawnmower blade is mounted to the face bar on a bolt extending through the face bar slot and the blade to have one of its cutting edges lying in a horizontal plane coincident with the grinding wheel axis. A blade positioning bar is mounted in the face bar slot and clamped up against the bottom edge of the blade. The angle of the face bar is set and the face bar clamped to the legs. The one cutting edge of the blade is sharpened by sliding the holder on the bench top to move the cutting edge into the grinding wheel. The blade is rotated end for end and reclamped to sharpen the other cutting edge.