How To Sharpen A Lawn Mower Blade

I have been an ardent gardener for the longest time.

From mowing my lawn to trimming the shrubs and bushes, I do it all. My husband rarely ever volunteers to take care of the lawn care department. And I don’t really mind since I love spending time amidst nature, maintaining the beauty of my pristine garden.

But I don’t really excel in fixing or maintaining power tools. So, when I realized that my lawn mower blade had turned dull and needed to be sharpened, I didn’t know how to go about it. I did think about getting it done by a professional; however, I didn’t want to give up without even trying.

So, I went over to my neighbor, Mr. Cooper’s place, for help. He knows everything about power tools, and as I had hoped, he explained all the steps involved in the process. And I noted them down for my benefit as well as yours.

Hi there! I’m Stacy Smith, and today, I’ll be teaching you how to sharpen a lawn mower blade. I’ve listed and highlighted the steps in detail to help you get a better understanding.

Let’s begin then!

How To Sharpen Your Lawn Mower Blade?

I usually inspect my lawn mower blade while mowing the lawn. And when it looks worn out and dull, I waste no time in getting it sharpened. Follow the steps given below to know how to go about this.

Steps To Sharpen Lawn Mower Blades

1. Shut Off The Lawn Mower

Start by shutting off the lawn mower engine and disconnecting the ignition wiring from its spark plug. This eliminates the chance of it accidentally starting, especially while you’re working on it. Here’s when you’ll also need to drain the fuel tank to prevent spillage.

2. Remove The Nut And Bolt

Next, position the lawn mower on its side to expose the nut and bolt, securing the mower blade to its underside. You may wedge a wooden block between the mower’s deck and the blade’s end to prevent the blade from turning.

Once secured in place, use a wrench and socket to loosen the nut and bolt. Now, when I tried loosening the nut of my mower, I noticed that its fastener was rusted. If you face a similar situation, apply some oil and wait for around 10 minutes before trying again. You may also consider slipping a metal pipe over the wrench handle to get better leverage while loosening it.

3. Remove The Blade

Remove the blade of the mower after removing its fastener while making a note of the side of the blade facing downwards. This is because you’ll have to ensure that it’s put back and secured in the same direction.

4. Clean The Blade

Once the blade is removed from the mower, take some time to clean by spraying it with penetrating oil and then scrubbing using a stiff-bristle brush. Use this time to also scrape and clean the lawn mower deck with the help of a putty knife having a narrow blade. This will allow you to remove the grass, leaves, mud, and other debris caked on it.

5. Clamp The Blade

All mower blades come with cutting edges, measuring 3 to 4-inch long on both ends, positioned at opposite sides. Now, it won’t extend the blade’s length, so make sure you clamp it at a suitable angle with either of its edges directing upwards.

6. Sharpen The Blade Using A Sharpener

Next comes the crucial part; you’ll need a drill-powered sharpener to sharpen the blade. Run it at a high speed by squeezing the trigger, and then slip the spinning tool over the blade’s cutting edge. Just ensure that the dull edge is facing the round abrasive stone of the sharpener while the flat sharpening guide is against the blade’s rear.

Start by slowly moving the sharpening stone in a back and forth motion (along the blade’s cutting edge) using moderate force. Do this four to five times, and then stop to check the blade’s sharpness. If needed, continue sharpening it till its edge is sharp. You may then remove it to sharpen the opposite edge.

Bestseller No. 1

SporGain [Updated] Lawn Mower Blade Sharpener 15°-45° Adjustable Frame with Ball Bearing Manufacture Handle for Right & Left Hand Blades, Use with Angle Grinder, Black

• [ Updated ] Lawn Mower Blade Sharpener: SporGain mower blades sharpener suitable for Blades standard straight, mulching and high-lift mower.
• Fits 1.65"–3.60" Mower Blades: lawn mower blade sharpener jig is designed to accommodate mower blades from 1.65" to 3.60" wide, making it suitable for a wide range of lawn mower blades.
• High-Quality Construction: This lawnmower blade sharpener jig firmly and securely holds the blades in place.

Buy on Amazon

Bestseller No. 2

Sharp Pebble Cordless Lawn Mower Blade Sharpener – Adjustable 20°- 40° Angle Guide-Rotary Tool with Replaceable Sharpening Wheel Bits & Fast Rechargeable Battery – Effortless Precision for Lawn Care

• SHARPEN YOUR MOWER BLADE IN MINUTES: Blade removal is optional with this cordless lawnmower sharpener — many standard residential blades can be sharpened right on the mower, saving you the hassle of disassembly. For blades that do require removal, the process is fast: sharpen in about 2 minutes per blade.
• ONE TOOL PAYS FOR ITSELF AFTER ONE USE: Replacement mower blades run $20–$40 each. A sharpening service costs money and a trip. This cordless lawn mower blade sharpener restores dull blades for pennies- own it once, use it all season, and never pay for a blade replacement again.
• GREENER LAWN IN DAYS - NOT WEEKS: Dull blades tear grass instead of cutting it, leaving brown stressed edges that take weeks to recover. A sharp blade creates a clean cut that heals fast — customers report visibly greener, healthier lawns within days of sharpening. This rotary blade sharpener delivers results you can see, not just feel.

Buy on Amazon

7. Balance The Blade

While sharpening, you might end up removing more of the blade’s metal from one edge compared to the other, causing an imbalance. And mowing a lawn with an unbalanced blade will cause wobbling, thereby damaging the motor of the mower.

I usually slip the center hole of my mower blade over a nail sticking out from one of my walls at home. Then, after holding it in a horizontal position for a few seconds, I let it go. You may do the same to determine if your blade is properly balanced. It has to remain in level, but if the end rotates downwards vertically, you’ll need to sharpen its heavier side to restore the balance.

8. Put The Blade Back

Once the blade is both balanced and sharpened, put it back into the lawn mower as it had been bolted initially. You may make use of a wrench to tighten the nut and bolt. Finally, attach the ignition to the spark plug, fill in the fuel tank, and then test out the newly sharpened mower blade.

Summing It Up