How to Sharpen Lawn Mower Blades With a Stone

You need a sharp blade for a beautiful, healthy looking lawn.

Cutting your grass with a dull blade not only rips or chops the grass off, leaving your lawn brown and dull looking, it will also leave your grass more susceptible to disease and sun damage. The engine of your mower has to work harder to cut the grass and your lawnmower uses more gas to get the job done. Therefore, it is important to keep your mower blade sharp to keep your grass healthy.

Things You'll Need

• Saw horses
• Penetrating oil
• Adjustable wrench
• Sharpening stone

Instructions

1. Place the lawnmower over two saw horses. This will keep dirt from getting in the engine parts. It will also keep you from having to drain the gas tank.

2. Spray the blade nut with penetrating oil. Allow to sit for several minutes before you try to remove the bolt.

3. Remove the blade nut that holds the lawnmower blade in place with an adjustable wrench. Hold the blade with your hand to keep it from turning or block it with a blade holder, sold at most lawn and garden centers.

4. Remove the blade. Clean all the grass and weeds off it before you begin to sharpen the blade. This will help you to see any nicks or chips in the blade that need to be filed out.

5. Wet the stone with water or oil if you have an oil stone. You don't need much water; just enough to act as a lubricant.

6. Hold the blade at the angle of the bevel as you move it over the sharpening stone. Most are around a 45 degree angle.

7. Drag the blade across the sharpening stone to smooth out any burrs that have formed. Remove as little steel from the blade as possible.

8. Move the blade across the stone in a circular motion on both sides.

9. Put the sharpened mower blade back on the lawnmower. Turn in the blade nut back into place and tighten it so it securely holds the blade in place. If your lawnmower has a torque setting, make sure you adjust it to the right setting. Consult the owner's manual for the right setting.

10. Reconnect the spark plug when the blade is firmly attached.

Tips & Warnings

• Wear heavy leather gloves to keep your hands from being cut by the sharp blade.

• If your blade is bent, you will to purchase a new one as it could break, resulting in injury or ruining the mower.

References

• Blain's Farm and Fleet: Sharpening a Lawn Mower Blade
• Geo Hunter: Sharpening Lawnmowers
• Lawn Mowers and Garden Tractors: Mower Blades Sharpening