Sharpening Mower Blades – What You Need to Know

Sharpening Mower Blades – What You Need to Know

Sharpening mower blades must be done with care by the do-it-yourselfer. The first priority is to disconnect the wire for the spark-plug. Then put on work gloves and get to work. When turning over the mower, keep the spark plug side up. Then hold onto one side of the mower blade to prevent movement. Take a wrench and loosen the nut on the blade.

Sharpening Mower Blades

Sharpening Mower Blades

After scraping and cleaning off the blade with a scraper, evaluate the condition. If the blade has been nicked by debris and rocks, you will need to replace it. If the blade is in good shape, you want to sharpen it. Sharpening a blade is important as a dull blade tears the grass instead of cuts it – all which is not good for the health of a lawn.

Manually Sharpening Mower Blades

Sharpening mower blades by hand comes easily to some people. Other people take longer to master the process. Therefore, it is helpful to learn what mistakes beginners make to avoid counter-productiveness.

For example, you need to focus on sharpening and sharpening alone if you want to see a good outcome from your work. Distractions, such as music or the TV, can break your sharpening rhythm. In turn, your blade will not be sharp or usable.

Sharpening mower blades by hand is done by first horizontally clamping the blade in a vise. Follow up by running a mill file that is bastard-cut across the edge. Use a downward stroke (one way) to sharpen the blade. Follow the current angle of the blade until the edge can cut paper, or is sharp as a butter knife.

A Faster Way to Sharpen a Mower Blade

You can also sharpen a mower blade by using an attachment for a sharpening stone and power drill. Mount the blade in a vise, keeping the cutting side up. Then place the sharpening stone inside the drill. The guide on the stone should be positioned next to the rear part of the blade to ensure the right cutting angle. Wear safety glasses when using the drill. Also, remember, blade edges do not necessarily get sharper by using a finer stone. A coarser stone will often suffice.

The Fastest Way to Sharpen a Mower Blade

The fastest way to sharpen a mower blade is to use a bench grinder. When you use this method, you need to be careful about sharpening the blade too much. This mistake is often made by beginners. If you over-sharpen the blade, you will remove too much of the metal, which shortens a blade’s life. When holding the blade then, place it perpendicularly to the bench grinder’s wheel. Sparks will be thrown. So make sure you are outfitted with safety glasses.

Before you re-fasten the mower blade, inspect its balance. You want to make sure the blade is even so it will not wobble. A wobbling blade causes the engine to work too hard. To ensure this does not occur, place a blade balancer on flat ground. Then position the blade on the balancer.

If the blade happens to dip, remove metal from the back portion of the blade. This edge is not part of the cutting edge. Instead, it is a part of the heavier end of the blade.Once you have the blade balanced, you can re-mount the blade, re-link the wire to the spark plug, and begin mowing your yard.

If you mow your yard in drier conditions, you may have to inspect the blade more often. A blade tends to wear more in these circumstances. Again, it is important to practice manually sharpening mower blades regularly. If you do not use sharp blades, you will place an additional strain on the mower’s engine.

Image Credit:

Flicker – Creative Commons

Photographer: Ian Payne


Wesley Kolbe

At the helm of AET Systems, Wesley Kolbe merges tradition with innovation to provide top-quality lubricants and unmatched service, ensuring every client's machinery runs at its best.