How to Sharpen the Blade on a Power Lawn Mower

Lawn mower blades lose some of their cutting ability after each use. Blades should be sharpened at least once per month during the times they are used frequently. The tips of your grass should be smooth after mowing; if they are jagged or rough, it is time to sharpen your lawn mower blade.

Difficulty:

Moderate

Instructions

Things You'll Need

• Pliers
• Vise grip
• Grinder or blade file

1. Turn the lawn mower upside down to access the blade. Use the pliers to remove the locking nut in the center of the blade. Remove the nut and the washers. Pay close attention to the order they are in, as you will need to keep them in the same order to re-install the blade.

2. Secure the blade with a vise grip. If you don't have a vise, you can perform this task on any flat workspace, but results are best achieved with the blade secure.

3. Slide the grinder or file over the edges of the blade. Try to keep your strokes uniform between sides. Sharpen the edges until they have a smooth finish.

4. Make sure the blade is balanced by standing it on an object in its center. The blade should be completely straight with no curves. If the blade isn't level, file the uneven side until it is.

5. Reinstall the blade on your lawn mower. Make sure you correctly install the nut and washers and make sure they are tight.

Tips & Warnings

• If you don't have a grinder or a file, remove the blade and take it to a machine shop for sharpening. Removing the blade will keep you from having to bring your entire mower to the shop.

References

• Blade Tips
• Sharpening
• Blade Sharpening