Before we get into how to sharpen your lawn mower blade, it’s first important to understand when you need to sharpen your blade. As a rule of thumb, blades should be sharpened once every twenty hours of mowing or so. For most lawns, this will mean sharpening your blades once at the beginning of spring, and once midway through the growing season. If you’re unsure how many mowing hours you’ve logged, an easy way to tell if your blades need sharpening is by taking a look at the very top of a freshly cut piece of grass. What does it look like? Is it cut cleanly across? Or is it raggedy? If it’s the latter, this is a good sign that it’s time to sharpen your blade.
Now let’s take a look at the specific steps and procedures you can take to sharpen your lawn mower blade.
- First, take out the spark plug. This is a crucial step because it ensures the mower won’t accidentally start (which, I can assure you, you don’t want happening while holding the blade).
- Access the blade by tilting the lawn mower directly backward (having a second pair of hands for this helps). Attempting to access the blade by tilting sideways can make oil or gas more likely to spill.
- When the mower is both tilted back and secure, put on a thick glove and hold the blade steady. Using your other hand, use the appropriate wrench to detach the blade.
- Once the blade is removed, the next step is to sharpen. There are a handful of ways to go about sharpening, but we’ll focus on the most common methods. (Note: before sharpening your blade, be sure to wear gloves, protective eyewear, and long sleeves.)
- The Grindstone Method. While this one is a bit more time-consuming than the others, using a grindstone is a tried-and-true method. Once the blade is properly secured into a vise, you’ll use a grindstone to sharpen the blade at about a 45-degree angle. Perhaps the most important thing to remember about this method is to only push the grindstone in one direction. In other words, don’t sharpen the blade going back and forth. Need a little help visualizing? No problem. Take a quick peek at this video to see how.
- The Drill Method. Happen to have a drill on deck? If so, this may be the most efficient way to sharpen your blade. To get started, you’ll need to purchase a lawn mower blade sharpener attachment for your drill, like this one here. Once you have this, you’ll place your blade in the vise and then position the grinder so that the flat guide is against the back of the mower blade. From here, you can turn on your drill and let the attachment do the work. Here’s a quick video to better help you visualize the process.
- The Specialty Tool Method. There are also a handful of specialty tools that may also be worth looking into, especially if you have other tools like shears, clippers, hatchets, or machetes that also need frequent sharpening. Tools like this one can sharpen pretty much any blade-based tool in your toolbox and make it incredibly easy to do so.
- When sharpening a blade, it’s possible (even likely) to remove more metal from one side of a blade, which can cause the blade to become imbalanced. This can be problematic not only for your grass but also for your mower. There are a few different ways to check this, but perhaps the easiest way is by using a screwdriver. Place the blade on a flat surface and place the screwdriver on the blade. If it balances nicely, you’re good to go. If it rocks back and forth, you know the blade isn’t properly balanced. This will mean you’ll need to remove a bit more metal from the heavy side of the blade.
- Once everything is balanced, you’ll then want to reinstall your blade and reconnect your spark plug.
Voila! You’re now ready to take on even the most daring lawn-cutting adventures. Now that you have the know-how to sharpen your blade, the final step is to integrate these blade sharpening procedures into your regular mower maintenance routine to ensure a crisp and healthy-looking lawn.