The Habitat
Home
Share to PinterestSharpening Your Lawn Mower Blades
Share to PinterestSharpening Your Lawn Mower Blades
Advertisement

People often make the smart decision and buy extra blades for their lawn mower, but regardless of how many replacements you have, you need to keep the blades working efficiently. A nicely mowed lawn is more drought-tolerant and resistant to disease. If you want your lawn to look neat stay healthy, the mower blades need to be sharpened after every 20 to 25 hours of use. Short of counting the actual hours, carve out dedicated time two or three times a year for this maintenance.

01

Knowing when mower blades need sharpening

Share to Pinterestlawn mower blades dented
nycshooter / Getty Images

One of the easiest ways to know that the blades need sharpening is that they look nicked and dented. Another sign is that the lawn mower isn’t cutting properly. This means that the edges of mown grass look ripped rather than evenly sliced; this stress can make the lawn turn yellow or brown.

Advertisement
02

Getting access to the blade

Share to Pinterestgas oil carburetor jack
philipimage / Getty Images

Removing the blades depends on the mower. First, make sure that the gas and oil caps are tight. Tip the mower back and away from the carburetor side, so the fuel doesn’t leak out. Some lawn mowers, such as tractor models, need to sit flat and allow you to remove the deck. With others, you can tilt the machine back with the help of a jack, giving you full access to the undercarriage.

Advertisement
03

Removing and cleaning the blades

Share to Pinterestremoving cleaning steel wool
BanksPhotos / Getty Images

Many mowers have a single nut fastener that needs to be removed with a ratchet before you can take out the blade. If the fastener is particularly stubborn, use some penetrating oil to loosen it up first. Once you’ve taken out the blade, remove all of the caked on grass and mud with a piece of steel wool. Cleaning is important, because you need to properly see the blade. Plus, if you’re using a sharpening tool with high RPMs, debris from previous mows will fly.

Advertisement
04

Working a bench grinder

Share to Pinterestbench grinder abrasive wheels
Oxana Medvedeva / Getty Images

A bench grinder is a grinding machine that uses abrasive wheels to sharpen edges. When using this tool, you just need to hold your lawn mower blade against the spinning wheel and draw it across until it’s sharp. The key is to maintain the blades’ curved angle while grinding one side at a time. It’s a good idea to wear goggles here, as the friction produces sparks.

Advertisement
05

Using a hand file

Share to Pintereststandard hand file
BanksPhotos / Getty Images

Using a hand file is labor intensive, but it allows sharpening at the proper contour, and doesn't require a separate machine. Apart from the standard file, you need a vise to hold the blade in place while sharpening. Before you start, make sure you're working the chiseled side and not the flat side. Maintain the same angle that’s on the blade and file on the downward stroke, not back and forth, as the latter can wear out the file too quickly.

Advertisement
06

Try a rotary tool

Share to Pinterestportable rotary tools
LarryHerfindal / Getty Images

Rotary tools, like a Dremel or a simple drill, have attachments that sharpen other tools, like chainsaw teeth. In addition to being portable, such tools are lightweight and maneuverable, so you can control it better to achieve a nicer edge. You can hold it in your hands and run the tool over the edge as many times as it takes.

Advertisement
07

An angle grinder is another option

Share to Pinterestvise stone disk
kampol Jongmeesuk / Getty Images

Many people use angle grinders to cut metal, but its abrasive wheels make it an ideal choice for getting rid of those nicks and dents in mower blades. Place the blade in a vise and fit the angle grinder with the grinding stone disk. Turn on the grinder and at an angle, run the tool along the beveled cutting edge, taking care not to press too hard.

Advertisement
08

The perfect angle

Share to Pinterest45-degree optimum angle
isuaneye / Getty Images

Sharpening at the right angle depends on the method. If you’re using a 10-inch file or a grindstone, working at a 45-degree angle helps you to keep the pressure even. A manual approach also helps you to feel how each stroke works and if you need to apply more pressure. For an angle grinder, the directions will tell you the optimum angle for use, which is between 20 and 30 degrees.

Advertisement
09

Check blade balance and reinstall

Share to Pinterestnail horizontal balance weight distribution
KathrynHatashitaLee / Getty Images

After sharpening, it’s a good idea to check the blade's balance, to ensure even weight distribution. Unbalanced blades rotating at thousands of RPMs cause vibrations that can stress the shaft and engine, reducing the useful life of your mower. To check balance, take a nail, and clamp it horizontally in a vise or tap it into the wall. Hang the blade on the nail from the middle hole. If it lists to one side, it means that side is heavy and needs more work.

Advertisement
10

Sharpening blades without removing them

Share to Pinterestspark plug empty gas tank
vavlt / Getty Images

If you have a non-tractor mower, it may be easier and less time-consuming to sharpen the mower without removing the blades. Along with the necessary work tools and safety gear, you need to disconnect all power sources and remove the spark plug, so there’s no chance that the machine will accidentally start. Empty the gas tank to reduce the chance of a leak or a potential fire. To prevent the blade from moving while sharpening, wedge a couple of 2x4 boards in key stabilizing spots.

Advertisement
Advertisement

Share

Ad

Make a habit out of it.

Get daily tips and tricks for living your best life.

Advertisement
Advertisement