Last Updated: 2 / 4 / 2023
If you want to get the best out of your lawn mower, whether it is gas, electric or battery-powered, you need to keep the blades sharp and your mower well maintained. It's also one of the top lawn care activities, and let me tell you, blade sharpening is no easy work.
Most of the time, just having your blades sharpened enough, but they occasionally might need replacement.
Related: How much to sharpen lawn mower blades?
In this guide we're going to talk about the ways you can get your blade sharpened.
First:
How do you know when to sharpen lawn mower blades
It depends on the type of device you own and the overall shape of the side of the blade.
If it's a sickle mower like the one you see in the right above picture, cutting edges of the blades will look frayed and feel dull to touch. Cuts you get from these horizontally rotating, flapping blades won't be clean as well.
If this is the case, you may consider sharpening or replacing the blades altogether to get better performance out of your mower. These types of blades are much cheaper compared to other mower types and widely available.
If it's some other type of mower, you own such as gas, battery, or electric powered, or even a robotic mower, you might actually need to flip the machine over to inspect the blades, and see if they look and feel dull. Other clues such as uneven cuts, ripped grass, and hard to push/drive mowers might give dull blade as well. When the blade is dull, it simply pulls the grass instead of cutting evenly. For robotic mowers, also check if the device visits the spots it already mowed more than a few times as it might indicate the blades need sharpening or replacement.
Read the manufacturer safety instructions.
It's very important to read the manufacturer manual to ensure safe operation. If your mower is powered by any type of motor, make sure it's switched off. For gasoline lawn mowers, disconnect the spark plug wire, for electric and battery mowers, disconnect them from their batteries or electric outlets. This ensures your device won't jump forward due to user mistake or mechanical failure and cause serious injuries.
Since it's impossible for us to tell you how to disconnect blades of every model of lawn mower out there, we suggest you refer to your owner's manual.
Consider hiring a professional
Depending on the model and make, it costs between 20 to 50 dollars to get your mower's blades as sharp as the first day. Most of the time it might not be the effort and risks. But if you've done it before and have taken necessary security measures, keep on reading;
What tools do I need for lawn mower blade removal?
To remove the blade, you're going to need a couple of basic tools. You most likely already own all of them, even if you don't, they come very cheap.
Allen wrench
Allen wrench, hex key, allen key, whatever you might want to call them... It's a simple tool that must be present in any workshop. The longer it is, the better actually, because it gives you more leverage, allowing you to get the job done using much less pressure and muscle power.
Adjustable wrench
Another tool I'm sure you have somewhere in your garage or home. These so-called spanners allow you to loosen up bolts and dismantle the blades safely.
Pipe wrench
A pipe wrench might also come in handy when disassembling bigger, heavy-duty machines. It's a must-have when you're dealing with larger and tighter screws.
What tools do I need to sharpen a lawn mower blade?
Tools we have listed above are used for taking the blades apart. The ones we're listing below are actually for sharpening them!
Before laying your hands on the blades, please wear protective gloves. We recommend the following tools for sharpening lawn mower blades:
Workshop file
Although some may prefer coarse file tools, I recommend circular workshop files. You could get either file cut 2 or 3. 2 means medium toothed, 3 means fine-toothed. Avoid a cut 1 file for better sharpening. You can also use a sharpening stone. Both will get the job done equally well.
Grinding machine - Bench grinder
I'm not saying go and get an expensive grinding machine just to sharpen your blades, but you might have a neighbor who already owns one.
If that's the case, grinding file very suitable for the final fine grinding and gets the job done much quicker than manual hand operated files.
Sharpen your lawn mower blades step by step
1. Turn off your lawn mower
2. Disassemble the blade using a wrench
3. Sharpen the blade with a grinder or a file
Please remember that you only need a butter knife-like sharpness because those blades turn at extreme speeds. Anything sharper than that and your blades will become dull again very quickly. It's also important to work in a well-ventilated area to avoid hazardous dust. Make sure to wear air filter masks to protect your lungs. If you're working on a high-speed grinding machine, also wear protective safety glasses in case a piece of blade breaks and launches into the air! After you're all done, simply reinstall the blade.