Project Guide: Sharpening a Mower Blade

Sharpening a Mower Blade

A sharp mower blade is critical to a good-looking lawn. Mow with a dull blade and you'll tear the end of the tiny blades of grass, creating a ragged cut that quickly turns brown, giving your lawn a dry, beige cast even if it's actually quite moist. Clean cuts with a sharp mower, on the other hand, promote good lawn health by preventing disease from getting a foothold in a sloppy, uneven cut.

Ideally, a mower blade should be sharpened once every month or two. It's easy to do and even all-thumbs types can do it quickly!

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Steps

Steps 1 - 5 of 5

Step One

First, remove the spark plug wire to prevent the mower from starting accidentally.

Step Two

Take off the blade with a wrench by removing the nut that secures it to the mower deck (the main part of the mower). You may have to wedge a piece of lumber between the blade and the deck to keep the blade from turning.

Step Three

Sharpen the edge of the blade using a file or a grindstone, keeping it at a roughly 45-degree angle, following the angle of the existing edge. Take care to even out rough spots.

Step Four

For a mower to run smoothly, the blade must be balanced, so take this opportunity to check the balance. Support the blade under its center with a rod or other narrow horizontal support, then spin it to check its balance.

Step Five

Replace the blade, taking care to knock out chunks of grass or mud that may have accumulated under the mower.

Steps 1 - 5 of 5