When your lawn mower isn't making the cut anymore, usually it's because the blade has lost its sharp edge from use. Removing the blade and sharpening it yourself can seem intimidating if you've never done it before. But it's actually a simple process, and you'll only need two tools to do it.
Once you know how to sharpen your lawn mower blade, it'll take you a fraction of the time it takes to mow your lawn. So, just follow this step-by-step guide to give your grass a crisp, clean cut again. Or, if you don't want to worry about sharpening the blade, you can just remove it and bring it to a lawn mower repair service near you to take care of it.
When grass blades have torn, ragged ends that turn brown after mowing, chances are it's time to give the mower blade some attention. Most experts recommend sharpening power mower blades once or twice a season, depending on how often you use your mower.
What You Need
- Wrench
- Medium file
Step 1: Remove Blade from Mower
Disconnect the spark plug on a gas mower or unplug an electric mower (to ensure the machine won't accidentally start while you're working on it). Next, gently lay the mower on its side and use a wrench ($28, The Home Depot) to remove the nut that attaches the blade to the motor. Then, remove the blade from the mower. To make sure you replace it the right way in the machine, mark the bottom of the blade with spray paint so you know that it should face the ground when you're done.
Step 2: File Blade
Clean any dirt or grass clippings off the blade with a dry cloth. Stabilize the blade in a vise and use a medium file ($12, The Home Depot) to smooth out imperfections along the blade edge (at the ends of mulching blades). Follow the existing angle of the blade, holding your file or sharpening tool at about a 45-degree angle. Move the file in one direction, gliding out toward the edge, much like you would sharpen a kitchen knife. However, your goal is to make the edge about as sharp as a butter knife rather than your favorite chef knife.
Step 3: Check for Balance
After you hone the cutting edge on both halves of the blade, check to see if the blade is balanced. An easy way to do this is to pound a long nail into a wall in your garage and rest the blade's center on the nail. If the blade isn't balanced, file a little more metal from the heavier side until it balances.
Step 4: Reassemble Mower
When the blade is correctly balanced, put the mower blade back onto the machine using a wrench. Be sure to tighten the nut securely back into place. And don't forget to reattach the spark plugs.
Should I Sharpen Mower Blades or Get a New Mower?
If you’re wondering whether it’s worth sharpening your lawn mower blades, the answer pretty much depends on the kind of mower you have, the ways you have used it, as well as how keen were you on maintenance to keep it in tip-top shape. Sharpening a lawnmower blade is considered basic upkeep and is a budget-friendly fix if your machine isn’t cutting grass as it should. When done properly, it’s quick and easy, and you’ll enjoy a clean-cut lawn every time. As a general rule, you can sharpen twice per season (say, six times a year if you omit wintertime) or after hitting solid surfaces, such as rocks, decorative pebbles, or layers of mulch. After several sharpening sessions–or a few years—if you see signs of uneven cuts, unhealthy patches of grass, or overall dullness when mowing, it’s recommended to replace the blades if the model you’re using allows it, or simply shop around for a newer, upgraded machine.