Wondering how to sharpen lawn mower blades without removing them from the machine? Sometimes one doesn’t have the time or the energy to remove and then attach those blades back.

Sharpen Lawn Mower Blades

That is why we bring you our tried-and-tested step-by-step guide on how to get sharp mower blades without taking them off. Read ahead to learn not only this but other useful tips from lawn experts as well.

How To Properly Sharpen Lawn Mower Blades Without Removing Them?

To properly sharpen lawn mower blades without removing them, you should tilt the mower on its sides, ensure all fuel has been removed, and if the lawn mower is electric, remove the batteries. Use a sharpening tool of your choice to sharpen each blade at an angle of 45 degrees.

1. Gather the Right Tools and Keep Them at Hand

Before you get down to the actual work, you need to make sure you have the right equipment. Trust us, organizing your tools beforehand will save you a lot of trouble later.

Right Tools Makes the Job Easy

You will need a wood block to support the mower, an angle grinder with a metal blade for sharpening the mower blades, and a steel file. You will also need a flat tire, a putty knife, and a wire brush to scrub clean blades.

Lastly, a bucket of water and good-quality soap is also essential. Don’t worry if you don’t own one or more items on this list. They are easily available online or in your local hardware store at quite reasonable prices.

2. Use Protective Equipment To Stay Safe

To ensure you don’t end up harming yourself, you must take care of yourself. Invest in a pair of premium-quality cut-resistant gloves to wear while you sharpen your lawnmower blades.

You will also need protective eye goggles made of thick and resilient material. Safety glasses will prevent things from getting in your eyes accidentally and causing problems.

In addition, it would be best if you could wear full-sleeved shirts, but it’s really up to you. Wear your most comfortable clothes and choose a day when the weather is nice to carry this out.

3. Seal the Gas Tank 

Take your mower to a flat surface and turn off its spark plug. This will prevent it from starting up accidentally while you are working. Apply parking brakes next, so it doesn’t start rolling away when you tip it later.

Seal the Gas Tank

Unscrew the lid covering the gas tank. Seal the opening with a plastic sheet or plastic bag as tightly as possible. Put the lid back on and tighten it. This step is important and will prevent fuel leakage from the tank once the mower is tilted.

4. Remove Batteries

If your mower is of the electric type, then there is no fuel tank to seal in this case. Still, you must ensure that its cord is unplugged from the power supply. 

Since you will be washing the blades, removing the batteries from the mower is necessary. Please remove the battery by disconnecting wires from both of its terminals. 

Then remove any bar or strap thing holding the battery in its position. Carefully store the battery in a safe place until you put it back later on.

5. Tilt the Mower on Its Side

Tilting the mower on its side will enable you to gain access to its blades. Make sure it is placed on a flat, stable surface and will not fall back. 

You can tell that your mower is tilted the right way when its fuel tank, air filter, and carburetor are facing upward. This is not only the best position to get access to the blades but will also make sure that no fuel leakage occurs from the gas tank.

Next, you need something to support the tilted mower with. The best option is to use a wooden block and place it diagonally on the opposite side of the mower. 

Don’t worry if you can’t seem to find a block of wood big enough to support the mower. You can use anything similar as long as it provides the right support to the mower.

6. Restrain the Movement of the Blade

Restrain the lawn mower blade, so it doesn’t move around while you clean and sharpen it. This will make your task ten times easier. It is also a kind of safety measure so that you don’t end up accidentally hurting yourself while working on the edges.

Restrain the Movement of the Blade 

A blade-locking tool will come in handy here. It will tightly secure the blade for as long as you want. Don’t sweat it if you don’t have a locking tool at home. Lawn mower blades can just as easily be locked using a block of wood or a pair of pliers.

When using a block of wood, choose one long enough to be stuck between the blade on one end and the mower deck on the other. Similarly, the pliers need also be locked between the blade and the deck to lock it effectively. 

7. Clean the Blades

Before sharpening lawn mower blades, they must be clean. Fill the bucket with soap and water for this task. First, however, you will need some blunt object to properly scrape off the dried dirt and grass stuck to the blade and the deck.

We use a wire brush as this is a tool that removes all stuck debris within minutes. It is best to clean the deck first and then move on to the blade. If you find it difficult to clean the blade because it has been stuck, you can wash it first and then secure it afterward. 

After removing the grass, wash off any remaining dirt or debris using the putty knife and a sponge. Use clean water at the end to ensure everything is spick and span.


8. Sharpen the Lawn Mower Blades

Now you are finally ready for the most important step of all. First, you need to decide what mower blade sharpening tool you will use. This mostly depends on op availability as well as what you are comfortable with. Your best options are using a metal file, a bench grinder, or an electric grinder.

Place the tool on the blade’s cutting edge at an angle of 45 degrees. Don’t worry about the exact measurement of the angle. Just follow the slant already present on the cutting edge and use your eyeball to make sure you sharpen it along it. For clarification, the cutting edge of the blade is one that faces the engine and not one that faces the grass.

While sharpening, move the tool in one direction, avoiding any back-and-forth motion. Secondly, don’t try to rush it by increasing your speed. Just go as steady as you can and utilize the entire length of the grinder in each stroke.

Go slowly from the center of the blade toward the edge. While at it, be careful of your hand, and don’t lose focus for even one second. How much to sharpen each blade depends on you. It is okay to stop when you feel the mower blade has been sharpened enough.

9. Don’t Forget To Unseal the Fuel Tank

After its blades have been sharpened, tip the lawn mower back to its original position. The first thing you need to do is open the fuel tank cap and remove the plastic you had placed over it to seal it.

In the case of an electric lawn mower, put its batteries back. Make sure to attach each wire to the right terminal of the battery. 

Unlock the mower blade by whichever mechanism you had locked it in earlier. Put the gas fuel back in the mower, attach it to the power plug, and start it back up.

10. Test Your Lawnmower Blades 

Put your lawn mower to work and test how well those blades have been sharpened. If it seems to be running and working as it was before then, this means your operation was successful. It’s time to give yourself a congratulatory pat on the back for a well-done job.

If weird vibratory noises seem to be coming from the mower while you cut grass during lawn care, you might have shaved one of the blades more than the rest. This naturally puts your mower out of balance and affects its performance. 

Another major sign of unbalanced blades is the grass cut poorly and unevenly. You cannot keep working with the mower in such a condition. It would be best to sharpen the blades again so they are balanced. You can have an expert do it for you this time if you don’t feel confident you have the required skills.

11. Resharpen the Blades After 20 Hours

It takes approximately 20 hours for lawn mower blades to become dull enough to need to be sharpened again. So if your lawn takes an hour to mow, then after 20 lawn mowings, you will need to repeat the whole procedure.

Resharpen the Blades

How often this happens depends on how much you mow your lawn as well as the condition in which it is kept. If you have planted a fast-growing grass type, you will need to mow more for efficient lawn care. This will get the blades dull much faster.

Similarly, if your lawn contains rocks and other hard debris, moving over these will dull the blades faster. Consequently, you will have to sharpen them more often.

Frequently Asked Questions

– Why Shouldn’t You Sharpen Both Sides of a Mower Blade?

You shouldn’t sharpen both sides of a mower blade to prevent affecting performance! Sharpening both sides equally will dull both sides much more frequently than otherwise. The grass-cutting efficiency is hugely impacted as well. Sharpening both sides of the blades might seem tempting, though, but you should avoid it.

It would be best if you did not sharpen both sides of the mower blades. Ideally, one side of the blades should be razor sharp while the other side needs to be dull, just like the blades of scissors.

– How Sharp Should Ride-on Mower Blades Be?

Ride-on lawn mower blades should be as sharp as a butter knife but not as sharp as a razor. As a general rule of thumb, you must be able to run your finger across the cutting edge without getting cut.

For the technical ones among you, the cutting edge needs to be at an approximate angle of 45 degrees.


So, is sharpening the blades of a lawn mower without removing them the easiest thing ever, or what? Here’s the summary of our guide:

  • Ensure you have everything ready and in order, before you begin, and don’t forget to don gloves and goggles for your protection.
  • Remove the fuel and batteries from the mower before tilting it to the side and jamming its blades.
  • Sharpen only one mower side using the tool of your choice at an angle of 45 degrees.

We understand why you don’t want to go through the hassle of removing and reattaching the blades of a mower every time to sharpen it. With the help of the information you digest from this guide, you will be able to sharpen the blades effectively and save yourself plenty of time. 

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