How to Sharpen Lawn Mower Blades

Have you ever mowed your lawn and somehow it looked worse AFTER you finished? If the blades on your mower are dull, they aren’t going to be able to cleanly cut through the grass. Instead, they will pull up on the grass, causing damage and making your yard look unkempt. Keeping your blades sharp and balanced will ensure that the grass is being cleanly sliced through at an even height, which helps keep your lawn healthy and the envy of the neighborhood. In this article, we’ll discuss four different methods for sharpening your lawn mower blades, and how to check that they’re balanced. Follow along with the video and continue reading below.

Using an Axe File

This is the simplest and most economical way to sharpen your mower blades. This method requires you to mount the blade firmly in a bench vise. If there are any burrs or chips in the top side of the blade, we’ll be able to see those and remove them first by using the coarse side of the axe file. Next, we’ll concentrate on the bevel side of the blade. If your blade isn’t chipped too badly, you can use the finer side of file, making sure to get the angle exactly the same as the bevel. Then use strokes from the cutting edge of the blade towards the back side. Be sure to only file off as much as you need to achieve a nice sharp edge.

Using a Lawn Mower Sharpener

This method uses a specific grinding wheel for a drill. This style of mower blade sharpening disc is available at most hardware stores and features a beveled edge and a guide disc that it’s mounted on. They will fit any quarter-inch drill or larger, and the wheel is also reversible. Once one side starts to wear you can remove it, flip it over, and have a fresh surface to work with. To sharpen the mower blade, place it in your bench vise so that it is secure. We’ll use the guide on the back side of the blade and allow the beveled grinding wheel to follow along the contours of the bevel on the blade itself. Take note of the direction that the wheel is traveling as we don’t want to allow it to pull away. We are going to pull it towards us, once again only removing as much material as needed to get the blade sharp. This method is a very simple way to get the proper bevel on your mower blade every time.

Using an Angle Grinder

Since an angle grinder turns at a much faster speed, it’s important to make sure you’re wearing the proper PPE, especially eye protection. Once again for this method, the mower blade will be secured in your bench vise. When using the angle grinder to sharpen the blade, you want to make sure that the direction of the grinding wheel is going from the sharp edge of the blade to the back edge, making sure you’re following the bevel angle. Mulching style blades typically have two cutting edges, so it can be a bit difficult to get the transition edge sharpened. If needed you can use a file for that particular spot, or gently pivot the angle grinder to access it. Once again, don't take off any more material than is needed to get that sharp edge.

Using a Bench Grinder

The previous methods all required securing the blade in a bench vise and using handheld tools to do the sharpening. This time we’re going to use a stationary grinder, whether it’s mounted to your floor or a bench, and we’ll move the blade itself along the grinding wheel. It’s important that you have a tool rest to sit the edge of the blade on. Once again, we’re going to grind from the sharpened point of our bevel to the backside of the blade, only removing the absolutely necessary amount of material to get that fresh edge.

Balance the Blade

While it’s important to get a nice sharp edge on our blade, it’s also important that it is properly balanced. The blades become unbalanced if you shaved off more metal from one side versus the other. Keeping them balanced ensures that not only will your lawn stay better maintained, but also helps the mower itself. If the blades are unbalanced, the speed at which they’re spinning can put too much stress on your mower. There are a couple of ways to check if your blades are properly balanced. The first is simply hanging the blade from a nail in the wall. If one side is heavier than the other, it will tip downwards. The second way is to purchase an inexpensive balancing cone. Similarly, you rest the center of the blade on the cone, and the heavier side will dip towards the ground. To correct an imbalance, carefully shave off some metal from the heavier side until it hangs evenly.

Buy New Lawn Mower Parts

We hope you found these tips helpful and that you’ll be able to implement one of these methods to keep your mower’s blades sharp! If you need any replacement parts for your lawn mower, you can find them easily by searching for your model number. Make sure you subscribe to our YouTube channel, so you don’t miss any updates!