How To Sharpen Your Lawn Mower Blades Without Removing Them

If you're one of the millions of Americans caring for your own lawn, you likely have limited professional expertise when it comes to lawn mower maintenance. And if you've been using the same push mower for years, you might have noticed your grass looks ragged and clumps of wet, torn grass are left behind instead of a clean cut. Luckily, there's an easy fix that many homeowners often forget — sharpening your lawn mower blades. It's a quick, simple way to keep your mower cutting cleanly and efficiently for years to come. This will extend the life of your lawn mower, especially if you commit to sharpening twice per season. 

Like any other blade, lawn mower blades can dull with time, causing them to tear at the grass rather than cutting it. This leads to clumps of grass being pulled out at the root and leaves behind a patchy look which is prone to browning, effectively ruining your lawn. As you can imagine, many homeowners neglect sharpening their blades because of the obvious dangers associated with handling the underside of a lawn mower. Fortunately, sharpening your lawn mower blades can be done safely using either simple manual tools or power tools, with a few straightforward steps.

Before you tackle those dull mower blades, take plenty of safety precautions: remove the battery on electric models, empty the gas tank on gas-powered ones, and disconnect any power sources that could accidentally spin the blades. Be sure to block the wheels so that the entire apparatus is locked into place while you're working, ensuring that nothing slips and sends the mower flying across your garage. Remember, wear a pair of thick gloves and eye protection throughout this entire process.

Once it's safe to proceed, jam a 2x4 board into the blade well to lock the blades in place. From there use a metal file to sharpen your blades like you would any other edge. Simply apply pressure in angular strokes from one end to the other. About five to ten minutes should do the trick — you just want the blades about as sharp as a butter knife to the touch.

Alternatively, an angle grinder can be a must-have tool for lawn mower blade sharpening. If this is your preferred method, be sure to use a flap wheel rated at 60-80 grit, and apply the same instructions outlined above. When you finish, sweep up any stray metal shavings and remove the 2x4 board so your mower can get back to cutting grass like a pro. Done right, your next lawn will look as fresh and even as the day your mower rolled out of the box.