The Best Method For Sharpening Your Lawn Mower's Mulching Blades

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Keeping your mower blades sharp is one of the keys to maintaining a healthy lawn and getting a good, clean cut. So, when you begin to see signs it's time to sharpen your mower blades, such as a ragged or uneven cut, you should do so immediately. However, the type of mower blade you have will determine how you sharpen the blade. While every method involves several similar steps, when it comes to the best way to sharpen your lawn mower's mulching blades, it is critical that you follow along the existing curvature of the blade.

The main difference between a standard mowing blade and a mulching blade is their curvature. Whereas a standard blade is straight with a single, angled cutting edge, a mulching blade is curved with multiple cutting surfaces. Just as you need to maintain the proper angle when sharpening a standard blade, you must stay consistent with the blade angle when honing mulching blades, following along the curving contour of the blade while maintaining this angle. With that in mind, it is typically best to utilize handheld tools such as an angle grinder or file, such as the WorkPro 10-inch Flat File.

The initial steps for sharpening your lawn mower's mulching blades are the same as for sharpening a standard blade. Begin by disconnecting the spark plug wire so as not to fall victim to an accidental starting accident. Then, remove the blade and clean it with a rag or brush. Next, place it in a vise, such as the Yost LV-4 Homeowner's Vise, so that it will remain in position while you are sharpening.

Once that is done, begin sharpening the blade by following the existing edge with an angle grinder or hand file. If you are using a file, be sure to only go in one direction with your strokes. It is usually best to start with the flat cutting surface, then sharpen the cutting edge on each curve of the blade in succession. After sharpening, check for any burrs and remove them with a few strokes of the file.

As is the case with sharpening a standard straight mower blade, you are taking metal off with each stroke. The same amount of metal must be removed from each side of the blade so that it remains balanced. Once you feel the blade is adequately sharp, check the blade's balance by placing it on a balancer. If one side tilts, that means it is heavier and a bit more metal must be removed. After sharpening and balancing the blade, it should be wiped clean and reinstalled on your mower.