How to Sharpen a Lawn Mower Blade

Learn how to sharpen your lawn mower's blade with these easy steps.

Related To:

Photo By: Photo by Debbie Wolfe

Photo By: Debbie Wolfe

Photo By: Photo by Debbie Wolfe

Photo By: Photo by Debbie Wolfe

Photo By: Photo by Debbie Wolfe

Photo By: Photo by Debbie Wolfe

Sharpen Your Lawn Mower Blades

If you mow your own grass, you need to know how to sharpen the blade on your mower. A sharp lawn mower blade saves time and energy while mowing, ensures a clean cut, and even helps to minimize the spread of lawn fungus.

Remove the Old Blade

Follow these steps to safely remove the old blade: Disconnect the spark plug. Tip the mower up on its side. The side with the carburetor and air filter should be on top. Block the blade with the piece of 2' x 4' or place a piece of 3-inch pipe through the side discharge and over the blade to hold it in place. Use the wrench to remove the bolt which holds the blade in place. Set the bolt and washer aside where they will not be lost.

The Old Blade Still Has Plenty of Life

You can tell if the blade is worth the time to sharpen or not. Once its removed, take a look at its thickness; this will let you know if you can still sharpen the blade.

Clamp the Blade to a Work Table

Clamp the blade in the vice in “cutting position”, with the first end to be sharpened extending 3 or 4 inches beyond the jaws of the vice.

File the Blade

Following the original angle of the cutting edge (approximately 30 degrees), and with long steady strokes, use the file to smooth the rough cutting edge back to a flat sharp surface. For quick grinding action, a double-cut file will remove a lot of material fast. For honing and creating a final edge use a single-cut file. Double-sided files are available with one side single-cut and the other side double-cut. When the first end is complete, reposition the blade and sharpen the other cutting edge.

The Finished Sharpened Lawn Mower Blade

Once both sides are sharp, check the balance of the blade by hanging it on a nail through the bolt hole.  If it hangs horizontally, it’s ready to reinstall.  If one end hangs lower than the other, file a bit more off that end’s edge until the blade balances on the nail.  This will ensure that the mower runs smoothly. Re-install the sharpened, balanced blade. Remember to use the 2' x 4' or pipe to stabilize the blade as you tighten the bolt. Reconnect the spark plug wire. You’re ready to mow!

Next Up

Tips for Watering Lawns and Gardens

Without adequate water, plants will suffer and eventually die. Supplies can run short as rapidly growing plants draw up moisture from the soil. It's important to know what to water and how.

How to Fertilize Your Lawn and Garden

Learn how adding fertilizer can be beneficial, especially for fruits, veggies and container plants. Fertilizers can also help kick-start growth after planting and reinvigorate plants that have been pruned hard.

Watering Lawns and Gardens

Thorough, careful watering encourages deep, drought-resistant roots in your lawn and garden. Follow the steps below to ensure best results.

Lawn Care Tips to Keep Your Lawn Green and Growing

Mow, water and fertilize on a regular basis to keep your yard looking lush and tidy.

How to Care for Your Lawn

Learn how to properly care for your lawn all year round with our expert tips on mowing, watering and feeding your grass.

Plugging and Sprigging a Lawn

Learn how to start a brand-new warm-season lawn or patch an existing one using plugs or sprigs. 

Landscape and Lawn Edging Products

Discover a range of lawn edging products and tips for creating crisp borders across your landscape

How to Plan and Design Your Lawn

Learn how to plan and design your outdoor grass and garden spaces with these landscaping tips.