How To Sharpen Lawn Mower Blades

Well, it’s that time of year again when everyone’s getting their lawnmower out ready to cut the grass. So let’s check if the lawn mower’s blade needs to be sharpened or not and if it does let’s sharpen it.

How To Sharpen Lawn Mower Blades (Step by Step)


Step 1. Disconnect the spark plug lead of the Lawnmower.

So the first thing you need to do is disconnect the spark plug. For safety purposes, you must remove the spark plug wire.

Step 2. Lay the lawnmower straight Up.

The next step is to tip the lawnmower straight up. Remember do not tip your lawnmower side to side. Because most of the time it leads to oil/gas leaking.

Step 3. Take the wrench to undo the bolt in the center of the blade.

The next step is to undo the bolt in the center of the blade. Just put on a glove, or hold the blade with a cloth wrapped. Now use the right size socket to undo the bolts. Because if you don’t use the right size socket for the bolt. Then you can round them off very easily.

Step 4. Remove the rust and grass from lawn mower’s Blade.

Now you can just take a paint scraper and take off as much of the junk as you can. After removing all the rust and grass from the blade. Let’s move onto the next step.

Step 5. Take a metal file and sharpen the blade.

Now you must be wondering why I didn’t choose an angle grinder or the lawnmower blade grinding tool. I’ll discuss that in detail in a few minutes. Personally speaking, I have used all types of tools to sharpen the blade. But my most favorite method is from metal files. Frankly speaking, I like the old school techniques much better. Although they are a bit time-consuming.

So now let’s talk about how to sharpen the blade. So first put your blade on the vice and then take the metal file and follow the same angle that the blade was originally sharpened at, And just draw your file along there until you’ve got a nice sharp edge. Just make strokes in one direction. To avoid any disbalance in the blade.

Step 6. Check the balance of the blade before putting the blade back.

After we’re finished sharpening it. We want to check it for balance to make sure that the lawnmower isn’t going to shake all over the place. So just take a nail and hammer it into the side of your workbench and then hang the lawnmower blade on the nail and it should balance out pretty evenly. In case it doesn’t balance out evenly than just grind off the extra metal from that side of the blade.

Step 7. Put the blade back on the lawnmower.

Now let’s put the blade back on and just make sure to put it back nice and tight. And lastly don’t forget to put your spark plug boot back.

Q & A

Is It Worth Buying a Lawnmower blade sharpener?

Lawnmower blade sharpeners are becoming very popular nowadays. You can buy one for under $10-$15. You just need to attach the sharpener to the power drill. And just put it onto the blade and start grinding. It’s easy, simple, and effective. You don’t have to detach the blade from the mower for sharpening.

But honestly speaking I don’t find it much helpful. I purchased one from Amazon for $11. And it takes around 10-12 minutes to grind the blade and with lower psi drills it performs the worst. It is better to just use the grinder. If you wanna give it a shot then it’s not that much expensive. You can go for it.

How often should you sharpen the lawn mower’s blade?

On average for a lawn of a quarter acre size, you should sharpen the blade 2-3 times per season. If the lawn is bigger than a quarter acre then you should sharpen it every 8 hours of use.

When to Change your Lawn mowers blade?

If the blade of your lawnmower is too thin and starts chipping at the edges and you are seeing mild cracks in the blade. Then it’s time to change the blade.

Lawnmower blade sharpening cost

On average the cost of sharpening a lawn mower’s blade is around $8-$10. If you sharpen it on your own then it’ll only cost time and nothing else. Don’t try to weld it because it can cause more harm than good

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