How To Sharpen A Lawn Mower Blade

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Having a sharp lawn mower blade will help maintain a green and healthy lawn. Watch as Ace's Home Expert, Lou Manfredini, shows you how a rotary tool can be used to quickly and efficiently sharpen a blade.

Why Sharpen?

Sharpening lawn mower blades doesn't only benefit your mower and its efficiency, but it benefits your lawn as well. When mowing the lawn with dull blades, it actually tears the top of the blades of grass instead of cutting it. This tearing action makes grass more susceptible to diseases or even a fungus. There's a -- dual edge -- to maintaining your mower blades, pun intended.

Just like having a sharp knife in the kitchen, having a sharp blade on the lawn mower will make cutting the grass that much easier.

Tools and Supplies

  • Cordless Dremel Rotary Tool: The attachments for the rotary tool are compatible with any of the other corded tools, however a cordless one is more convenient, allowing you to sharpen blades, even if you are not by an outlet. Dremel tools are light weight, moveable and offer maximum control.
  • Dremel Sharpening Kit: These are specialty attachments that go on the end of the rotary tool. These attachments can sharpen other garden tool blades as well as chainsaw blades.


  1. Make sure the fuel tank to the lawn mower is empty
  2. Make sure the fill tube to the oil tank on the mower is firmly closed, because you will need to tip the mower on its side
  3. Loosen the nut at the center of where the blades are attached to remove the blade
  4. Attach the grinding attachment to the end of the rotary tool, pressing the lock button as you tighten it securely onto the end.
  5. Slide the blade sharpening attachment from the kit on top of the grinding tool and tighten until it is snug.
  6. Wear safety glasses before starting to use any tools.
  7. Turn on the rotary tool.
  8. Line the attachment up with the side of the blade and run the grinding stone along the edge.
  9. Only sharpen the cutting portion of the blade. It should be apparent where this is
  10. Repeat this same process to the other side of the blade
  11. Reattach the blade to the bottom of the lawn mower. And with that, you're done!

For more helpful tips and advice, visit Ace Hardware's Tips & Advice or a local Neighborhood Ace
Published on 9/2/2021.

Always follow manufacturer's instructions before using any product.
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