How To Change Lawn Mower Blade

By Desmond J.

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A blade is an essential part of the lawn mower. After many hours of usage, the mower blades easily wear out. For this time you have to sharpen or replace mower blades.  For saving our precious money we can sharpen mower blades several times to extend their life.  

However, a dull, broken, damaged or a missed patch mower blade can cause a number of easily noticed symptoms.

Dull or broken blades create excessive vibration and damage the grassroots and it’s easily noticeable.

Once you notice these symptoms, then it’s time to change the blades.

How Often Should I Change My Lawn Mower Blade?

It’s the most common question. We heard it lots of the time. 

MowersLab experts recommend you have to change the mower blades annually. Also if you provide lawn mowing services then after many hours of usage you have to change it.

But it fully depends on grass-cutting performance.

How To Change Lawn Mower Blade?

Luckily changing the mower blades is easy if you pay attention to our step-by-step guide. If you are equipped with the right tools it will finish within 30 minutes.

We separate it into two easy steps. 

  1. Remove the old bales 
  2. Install the new one. 

How To Remove The Old Blade

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Unplug The Spark Plug

To avoid the accidental star, we highly recommend you please the remove mower spark plug first. It is the best safety procedure that can prevent electric flares in case oil or gasoline comes in contact with the spark plug. It shouldn’t be an important thing if you hold the mower in the right position, but it’s still best to be on the safe side.

Lift The Mower Deck To Expose The Blade

Before lifting the mower deck takes a closer look at the mower carburetor and mower engine. Don’t lift the mower at the carburetor or engine side. Before tilting the machine, drain the oil or gas from the carburetor so that it can not be spilled on the ground or engine.

However, if you can not drain out the oil or gas make sure that the gas or oil tank is properly secured and there is no chance of licking the oil. 

Use hedge support and slowly tilt up the mower side. Now you easily reveal the mower blades beneath. 

Also, if you’re still confused about it we recommend please read the mower manual.

Remove The Blade Mounting Bolt

Put heavy working gloves and use a socket wrench of the appropriate size and unbolt the mounting. Use your hand and keep the blade from turning. 

Note: Don’t lose any hardware, washer, and blot when you remove the mounting bolt. It can be reused. 

Pay attention to the positing of blades that you are removing. New blades will set in the same orientation for ensuring an efficient cut. Usually, the blade sharp edge goes counter-clockwise with the turning of the assembling. But, this may not be true for all other mowers, so pay attention when you remove the installed blade and install the new one accordingly. 


Because new blades will be installed in the same direction. Otherwise, you won’t get the good cut. 

Installing New Blade

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Purchase Replacement Blade

It’s a wise idea to purchase the new blade from the same store or online in which you bought the machine. A replacement blade kit for the push mower is usually for a few dollars at most stores or outlets, it features new pre-weighed and sharpened blades and replacement nuts.

Some classic mowers have a bottom cap with two shorter separate blades attached. 

But the newer mower features single longer blades that look like a ruler. 

Tilt the mower back and inspect the blades or take it to someone at the hardware store about the type of blade that is suitable for your mower.  Or you can also check the mower manual. 

Note: Alternatively you can salvage the old bale and have them sharpened if they can be back and seem to be in decent condition. 

If the blades are worn out with chips or chunks out of the metal, we highly recommend it wise to get a new set. 

Mounting The New Blades

Now mount the new blade in the appropriate direction.  Using the new or old washer and nuts of appropriate size and lineup the new replacement blade in the right position. Consult the mower manual if you have or check the mower brand’s official website for finding the directions for torque specs needed to tighten the nuts. Also, we highly suggest you don’t over-tighten the nuts as this can cause unwanted vibration in the mower. 


  1. Before purchasing the blades be sure that the replacement blades have the same length as the old ones.
  2. Don’t over tighten the mower blades
  3. Reading the mower manual to ensure everything is fine.
  4. Use your hand, hedge, or tiny wood to stop the rotating the blades during the mounting 

Check The Blade For Play

Be sure that the mower blade is mounted correctly in the appropriate position. Before starting the mower make sure it has not wobbled while you move it up or down and it has been secured firmly to the engine drive shaft.

Refill The Gas Tank And Do A Pre-check Before Mowing.

Before starting the mowing job, refill the gas or oil tank and wait 30 – 60 minutes for the circulation of fuel.

Also, check the mower air filter and make sure it is not dusty or clogged. If you found it dusty or coggled see out this guide. 

Finally recheck the spark plug wire and sure that it has good condition before replacing it. After everything is done, take a quick look and make sure everything is in optimal condition and switch on the mower.


Changing the mower is easy with these few steps. It’s not a lengthy process. 

We hope all information has enhanced your knowledge about how to change the lawnmower blade and also if you enjoy our guide make sure that you sign up for our newsletter where we share incredible guides that we do not share publicly. You will find it in our footer section.

Happy gardening!

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Written By
Desmond J.
I'm a lawn mowing expert and gardening enthusiast. I started my own lawn care business in college and have been doing it ever since. I love taking care of lawns and gardens, and I'm always looking for new ways to improve my skills. I'm also a big fan of composting and using natural fertilizers.

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