- 1). Put on the eye goggles and leather work gloves. This will protect your eyes from any flying debris and metal and protect your hands. Examine the mower blade. If the blade has cracks or splits, throw it away and purchase a new blade. If the mower blade just needs sharpening notice the factory angle on the cutting edges of the mower blade.
- 2). Fill a bucket with water. Turn the bench grinder and grind the tapered cutting edges of the mower blade to remove any nicks in the blade. Follow the factory edge and move the blade across the grinding wheel.
- 3). Dip the mower blade into the bucket of water to keep the blade cool. Wipe the blade with a rag and continue to grind the nicks from all of the cutting surfaces of the mower blade. Do not overheat the blade while grinding because this can cause the blade metal to weaken and warp.
- 4). Set the lawn mower blade in a bench clamp with the cutting edge facing up. Use a mill file to file the edge of the cutting part of the blade. Keep moving in long upward strokes and follow the factory angle. Use firm pressure while filing the blade. When one edge is complete, unclamp the blade and turn the blade around to file the other cutting edge.
- 5). Set the plastic balancer on a flat surface such as the shop floor or the work bench. Place the center of the blade over the plastic balancer. The blade should balance on the balancer. If one side of the blade sits down on the flat surface, grind some metal on the non-cutting side of the heavy end. Set the blade back on the balancer and recheck the balance.
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