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Do I Need to Change the Lawnmower Blades?

Despite your regular lawn care efforts, your lawn doesn’t seem to look its best. You may be wondering what’s causing this issue. The problem may not be with your mowing technique but rather with the condition of your lawnmower blades.

Changing your lawnmower blades is an essential part of maintaining a healthy lawn. Worn-out or damaged blades can tear and damage your grass, leading to an unsightly and unhealthy yard.

But what if you’re confused about “Do I need to change the lawnmower blades” or replace them?

Inspect your mower blade for damage, sharpen after 25 hours of use, and replace it yearly or after 200+ hours for optimal grass cutting.

Want to read a complete guide on how to sharpen your lawn mower blade? Click here!

I am here with all the necessary information regarding when to replace or change the lawnmower blades with pro tips. By the end of this article, you’ll better understand whether your lawnmower blades need to be replaced to help you achieve an aesthetically manicured lawn.

How Often Should Lawn Mower Blades Be Replaced?

It is advisable to replace the blades of your lawn mower a minimum of once every year( or at least 200 hours or longer), preferably before the start of the mowing season. However, if you notice any signs of damage, you must replace them immediately. Additionally, if you hit any rocks, roots, or other hard objects while mowing, you should inspect your blades for damage and replace them if necessary. Mower blades require sharpening every 25 hours or replacement if damaged severely.

Another factor to consider is the type of grass you have in your lawn and how large your property is. Some grasses, such as Bermuda grass or zoysia grass, require a more precise cut than others. If you have one of these grasses, you may need to replace your blades more often to ensure they are sharp enough to provide a clean cut. Likewise, If you have a large lawn you may need to replace the blades more often.

Also Read: Best Electric Lawn Mowers for Your Garden

When to Replace Lawn Mower Blades?

Sometimes just sharpening the blade can solve the problem, but sometimes changing the lawn mower blade becomes inevitable. Consider these indicators to determine whether it is appropriate to sharpen or replace a lawn mower blade.

Also Read: How to Winterize Your Lawn Mower in 10 Easy Steps?

Chips or Dents That Matter for Grass Health 

If your lawnmower has large dents and chips that can be spotted easily, they are a warning sign for grass health. It may tear or sometimes even pluck them from the root and can increase the risk of diseases in your lawn.

Unbalanced Blade 

If your lawn mower blade cannot be balanced after sharpening or cleaning, it’s time to replace it. An unbalanced blade can cause the mower to vibrate excessively, damaging the engine and other parts.

Blade Has Damage that Cannot Be Repaired 

Sometimes mowers get damaged real bad, and sharpening doesn’t help at all. In this case, the only solution we have at hand is to change the lawnmower blades.

The Blade has Become Thinner 

If you’ve been using your tool for a long time, you have sharpened it several times. And due to frequent usage and sharpening, the metal has become thinner, and there is no room for further sharpening. Now you need to replace the blade because further sharpening will not make any beneficial difference.

Your Lawn Mower Blade is Bent 

If your lawn grass is cutting unevenly and the mower is vibrating too much, producing strange noises, or even stalls, it is a sign that your lawn mower blade is bent and needs replacement.

If They Are Older than a Year 

If you’re a budget-minded person like me, you use your devices for as long as they can accompany you. Then your mower’s blade has exceeded its usage limit and turned the grass pale and uneven. Don’t let it ruin your grass, and immediately replace it.

Step-By-Step Guide to Replace Lawnmower Blade

Replacing a lawnmower blade can be done using the following steps:

Step 1: Disconnect the ignition wire and evacuate the gas

Change the lawnmower of blades
Covered the fuel tank with a plastic bag to change the lawnmower of blades

For safety, it is important to disconnect the spark plug wire(additionally can wrap it up with a plastic bag) and drain off the fuel(cover the fuel tank with a plastic bag) to prevent the engine from accidentally starting up and to prevent the gasoline from leaking out of the tank and creating a fire hazard.

Do i need to change the lawnmower blades?
Disconnected the spark plug
Do i need to change the lawnmower blades?
wrapping it in the plastic bag
Do i need to change the lawnmower blades?

Step 2: Tilt the mower

Do i need to change the lawnmower blades?
Tilt the lawnmower to start changing its blades

Tilt the mower on its side, ensuring the carburetor and air filter are up; otherwise, the crankcase vent will toss the oil into them.

Step 3: Remove the blade mounting bolt

Do i need to change the lawnmower blades?
Removing the bolt using vise grips

Remove the blade mounting blade with a ratchet (make sure you have locked it with a mower deck using a pair of vise grips so it won’t spin), lift the bolt off the spindle, and remove it from the lawnmower.

Do i need to change the lawnmower blades?

Step 4: Note the position of the blade

Do i need to change the lawnmower blades?
Compare the old and new blades

When you have removed the blade, remember to notice the bottom of the blade so that you can compare both and place it in a position like the old one. Inspect the new blade to ensure it matches the old blade in size and shape. Also, ensure the new blade has the same mounting holes as the old one.

Step 5: Mount the new blade

Do i need to change the lawnmower blades?

Place the new blade onto the spindle and ensure it is seated properly.

Step 6: Check the blade

Do i need to change the lawnmower blades?

Replace the bolt and tighten it with a wrench. Be sure to torque the bolt to the manufacturer’s specifications.

Step 7: Reattach the spark plug wire

Do i need to change the lawnmower blades?
Reconnect the sparkplug

Once the new blade is securely attached, turn the lawnmower back over, reconnect the spark plug wire, and remove the baggies.

Step 8: Start the mower 

Do i need to change the lawnmower blades?
Wait 10 minutes and then start the lawnmower

Please wait 10 minutes and then start the mower; it is ready to shape your lawn as you want.

Watch this video: How to Replace your Lawn mower Blade in 3 Minutes EASY WAY

Common Mistakes Homeowners Make When Replacing Lawn Mower Blades 

  •  Assuming that frequent sharpening prolongs the mower blade’s lifespan.
  • Without realizing whether it is necessary to replace the blade or not. 
  • Forgetting to empty the fuel tank before tilting the mower on its side.
  • Trying to replace the blade without adequate knowledge or experience.
  • Using a dull or damaged tool 
  • Forgetting to disconnect the spark plug
  • Improper tightening of the blade 
  • Using the Wrong blade for replacement 
  • Installing a blade with a center bolt hole that is larger than the recommended size results in an imbalance, leading to heightened levels of vibration.
  • Inverting the position of the mower to the incorrect side.
  • Fitting the blade upside down 

Also Read: How To Clean A Riding Lawn Mower Deck? Separate Methods for With or Without Washing Port

Reasons You Should Have Spare Lawn Mowers Blades Around

If you’re a person who often forgets to refill your tool inventory Keeping spare blades around you is important due to several reasons:

  • Uninterrupted Work: Keeping spare blades in your tool arsenal can save you from getting frustrated due to dull or damaged blades in the middle of the operation.
  • Increase Work Efficacy: If you have multiple blades of different types in your tool kit, you can swipe them immediately according to your need. If you want to mow the grass only, you can use standard blades, but if you also want to mulch, you can swipe them with a mulching blade
  • Ensure Safety: Dull blades can cause serious injuries to your grass and tool. And changing the lawn mower blade at the proper time is necessary; if not replaced, it may cause safety inconveniences to you.
  • Cost Effective: If you do frequent lawn maintenance or are professional, buying blades in bulk will benefit you greatly because buying in packs is more economical than an individual blade.
  • Help to Maintain an Aesthetically Pleasing Lawn: Sharp blades contribute to healthy grass growth and prevent the grass from the risk of uneven cuts and yellowness.
  • Maintain a Healthy Lawn Grass: If you have a bagging tool in your spare tool vault, it can help you from preventing pests, fungus, and weeds that can accumulate if you don’t bag your clipping while mowing, especially if you have tall grass.

Now you have learned about how to change the lawnmower blades, you might as well want to learn 5 Tips to Mow Your Lawn Like a Professional ‎


Blades are the most vital part of a lawn mower, and if you don’t know “how to change the lawnmower blades” you can lose the mowing game. And if you’re still thinking, “Do I need to change the lawnmower blades or not?

Then you should inspect your blade thoroughly; if the damage is visible and affecting your grass, you should change it. On the other hand, if you’re using these blades for more than 25 hours, they need to be sharpened. One more thing which is recommended for blade maintenance is to replace them a minimum of once every year( or at least 200 hours or longer)


How to sharpen lawnmower blades without removing them?

Sharpening lawn mower blades without removing them is not recommended and may not provide desired outcomes, but if you are a pro and know the technical aspects as well, the steps are as follows:

  • Seal the gas tank and turn off the lawnmower 
  • Place the lawnmower on its side with the carburetor and air filter facing up 
  • Hold the blade with the wrench or the plier 
  • Place a wooden block transversely to keep it in a stable position 
  • Remove the dirt and debris from the blade 
  • Now sharpen the blade either with a manual sharpener or an electric grinder maintaining a proper angle.
  • Make sure you have sharpened both sides 
  • After completing the process, unseal the fuel tank( gas mowers) and bingo.

What are the consequences of using dull or damaged lawn mower blades?

Using dull or damaged blades has a lot of serious consequences, including 

  • Uneven cuts 
  • Ripping and tearing of grass 
  • Time-consuming lawn mowing experience 
  • Increased fuel consumption due to more pressure on the engine 
  • Aesthetically hideous lawn appearance (yellow, brown raggedy)
  • Increased maintenance cost of the mower 
  • This makes the grass vulnerable to diseases, pests, and dehydration due to rough cutting.

Can I replace my lawn mower blades myself, or do I need to hire a professional?

You can replace your lawn mower blade if you have proper know-how of the tool and have prior experience with such procedures. If you lack experience or the appropriate equipment, it’s better to ask the expert to complete the task. This will ensure that the blade is installed correctly and safely. The warranty of some lawnmowers may also require that the blades be installed by a professional.

What type of lawnmower blades should I purchase as a replacement?

The type of lawn mower blade should be according to your tool, the type of grass, and the terrain you need to mow. For instance, if you’re planning to mow cool-season grass, you prefer a high-lift blade, and for warm-season grass, you can choose a low-lift blade.

Similarly,, for long grass, gator blades are good, and for mulching, blades need to be installed.

Similarly, if your lawn has sandy soil or rigid grass, use a flat lawn mower blade, and if you need to invest more in your tool to save time, you can look for self-sharpening lawnmower blades.

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