Practice safety when sharpening mower blades.

The Best Way to Sharpen Mower Blades

by Keith Dooley

Mower blades are an integral part of any lawn mower. Made of hardened steel, properly sharpened mower blades produce a clean cut that helps to keep grass healthy and a yard looking good. Over time, mower blades will become dull due to normal use. Sharpening mower blades is a basic maintenance project that a homeowner can accomplish with a few basic tools.

1. Consider Safety When Handling Mower Blades

Safety should be a primary consideration any time it is necessary to handle a mower blade. Even before the blade removal process is started, the spark plug wire should be removed from the spark plug. When working on a riding mower, make sure the transmission is in gear and the parking brake is set to prevent the mower from rolling. Safety glasses and work gloves are essential and should be worn to protect eyes from debris and hands from jagged or sharp edges on the mower blade.

2. Choose the Right Tool for the Job

A few basic tools are needed to sharpen a mower blade. When removing the blade from the mower, an adjustable wrench is effective. The ability to adjust the wrench to fit a variety of nut and bolt sizes helps make the blade removal process easier. A bench vise will hold the mower blade securely in place during the sharpening process and allows both hands to be free for work. A metal file is used to perform the actual sharpening of the mower blade. Files are manufactured by various companies; however, a basic metal file should be 1 inch or wider with a comfortable plastic or wood handle.

3. Sharpening the Mower Blade

Obtaining a proper edge on a mower blade requires that the file be used at the correct angle. The blade should be mounted in the bench vise with the beveled edge of the blade facing up. The metal file should be held at a 45-degree angle or matched to the beveled angle of the blade. Use long and smooth strokes of the file along the entire length of the beveled cutting edge to produce a sharp edge. Use the same number of file strokes on both ends of the blade. This will help to keep the blade in balance by removing approximately the same amount of metal from both ends.

4. Check the Blade Balance

A blade that is out of balance will result in vibration to the mower and an uneven cut on the lawn. Checking the balance on the blade is as simple as inserting a screwdriver through the bolt hole of the blade and then holding up the blade. If the blade is balanced, it will remain level and horizontal. If it dips to one side, some additional filing is necessary to remove metal along the cutting edge. A few strokes of the file will usually remove enough metal to balance the blade.

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