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Can You Sharpen Lawn Mower Blades Without Taking Them Off?

you need to sharpen your lawn mower blades regularly. Dull blades can tear the grass and make it more prone to disease.

But can you sharpen the lawn mower blades without removing them or taking them off?

The answer is Yes, you can. There are some ways to sharpen lawn mower blades without taking them off, but they have some drawbacks.

You will need a few pieces of equipment to sharpen the blade without removing them. Since it will still be on the lawnmower while you sharpen them, you have to be very careful about personal safety too.

How to Sharpen a Lawn Mower Blade Without taking Them Off

Here we are gonna talk two methods –

use a drill-powered blade sharpener

One way is to use a drill-powered blade sharpener. This is a device that attaches to a standard drill and has a grinding stone with a beveled edge.

You can clamp the mower blade in a vise and run the sharpener along the cutting edge, following the original angle of the blade.

This method is quick and easy, but it may not give you a very precise or even sharpening. You also have to be careful not to overheat the blade or remove too much metal, which can weaken the blade.

Using Hand File or Metal Rasp

Another way is to use a hand file or a metal rasp. You can turn the mower on its side, making sure the carburetor and air filter are facing up, and block the blade with a piece of wood.

Then you can file or rasp the blade along its edge, following the original angle. This method is cheap and simple, but it may take a lot of time and effort.

You also have to make sure you file or rasp both sides of the blade evenly, or else you may create an imbalance that can damage the mower.

But What is The Best Method to Sharpen a Lawn Mower Blade?

The best way to sharpen lawn mower blades is still to remove them from the mower and use a bench grinder or a belt sander.

This way, you can ensure a consistent and accurate sharpening of both sides of the blade. You can also inspect the blade for any cracks or nicks that may need to be repaired or replaced.

Removing the blade may seem like a hassle, but it will pay off in the long run with a better cut and a longer-lasting blade.

Why Sharpen a Lawn Mower Blade

You may be thinking even if the blade is not sharp enough it will tear through the grass. So why do I need to sharpen the blades in the first place? The answer to the question is to avoid pests and brown grass.

If the blade tares through the grass instead of cleanly cutting them, they become more prone to pests. This can also lead to the grass becoming brown and die out. So, a sharp blade is necessary to have a healthy lawn that looks nice in your backyard. The best lawn mower blade sharpeners will provide you with the best result all the time.

Why Sharpen a Lawn Mower Blade

Addressing Safety before Sharpening

Since we will be sharpening the blades without removing them, we have to make sure the engine doesn’t turn on while sharpening. For that, we have to first unplug the spark plug. If your lawnmower is a battery-powered one then remove the batteries.

Then, we need to drain the fuel tank if it is not a battery mower. That is because we need to tilt the mower to the side to get access to the blades. This action will spill any fuel that is inside the tank. If not careful, it can lead to a big accident. You can skip this step if you have a battery mower since they don’t need any fuel.

Other than that, you can also use hand gloves to make sure you don’t get hurt by the blades while sharpening. Another thing you can use is a woodblock to stop the blades from moving around. We will discuss this more in the next section.

Equipment Needed for Sharpening Lawnmower Blades

For this, you will need a file to do the sharpening. This can be replaced with a drill grinder. But to use a drill grinder you need to have a handheld drill. You will also need to use a scraper to scrape up all the extra materials from the blades. This will make the blade perform even better. All of these items can be found on Amazon.

You will also need gloves and a woodblock for safety. If you find that you can just grab the blade to stop it from moving. And it doesn’t hinder the sharpening process then you can skip using the woodblock. 

Another thing better to use but not necessary is a pair of goggles. This will protect your eyes in case of any stray bit of metal. Although many people don’t use them we recommend you using the goggles if possible.

Equipment Needed for Sharpening Lawnmower Blades

Sharpening the Blades of a Lawnmower

Now that we have all the tools and safety in check, we can start sharpening the blades of the lawnmower. First, make sure the lawnmower is not connected to the power source. So check the spark plug or battery (depending on which type of mower you have) and pull them out if you haven’t done it before.

Next, tilt the mower to its side to reveal the blades underneath. Here you need to make sure that the carburetor and fuel tank are on the top. After tilting, place the wooden block across the blade diagonally to fix the blades in their position.

Cleaning up the Blade

Before you start sharpening it, you need to clean the blade. Use the scraper to scrape anything that is on the blade. It can be some extra soil and grass or if the blade is older, then sometimes some rust too. Cleaning the blade will make sure you can sharpen easier and get the best performance out of it.

Cleaning up the Blade

Using Metal File to Sharpen 

After cleaning the blade, take the file and start sharpening the blades. To sharpen the blade, you need to press the file against the blade’s dull area at an angle. Try to maintain the proper angle of 45 degrees while sharpening. Keep doing that and slowly come downwards until the whole dull area has been sharpened.

Using Metal File to Sharpen 

Using Drill Grinder to Sharpen

If you are using a drill grinder then it is even easier to sharpen the blades. You can find these things on Amazon for 3-5 USD. These grinders can be attached to a hand drill and have a plastic frame along with the grinder. It makes sure the angle is right.

To sharpen with it, set the grinder inside the drill with the plastic frames intact. Make sure the plastic frame is touching the drill or else it will move back when you put pressure onto it. After setting up, place the blade between the plastic frame and the grinder. Now turn on the drill and it will sharpen itself.

Continue this process to the whole blade. This is less time-consuming and easier than using the file. But it will cost you more if you don’t have a smaller size handheld drill machine in your tool collection.

Using Drill Grinder to Sharpen

Lawn Mower Blade Sharpening Vs Replacement

Usually, you should check if it has become dull or not. If you find the blade has become dull then you need to sharpen it. You can also check the grass to find out if it has become dull or not. A dull blade will tear through the grass because of the force. But a sharp blade will cleanly cut them.

A good rule to follow is sharpening the blades before every mowing season. Then as the season progress sharpen the blade as needed. But if you find your blade has become rusty or bend then it is time to change the blade altogether.

A bent blade can be fixed by taking it to a workshop but if it is an older blade then changing it will be always a better option.


  1. Can you sharpen a mower blade too much?

Ans: Yes it is possible to damage the blade by putting too much pressure and sharpening too much.

  1. How often should mower blades be sharpened?

Ans: Depending on the usage a lawnmower blade needs to sharpen after 20-25 hrs usage.


Even though it is not seen as much, sharpening the blades without removing them is a very viable option. This way you don’t need to waste your time figuring out how to remove the blades. But it can be a bit awkward to sharpen it depending on the model of the lawnmower. Nonetheless, it does get the work done perfectly.

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