Do Brand New Lawn Mower Blades need to Be Sharpened

Do Brand New Lawn Mower Blades Need to be Sharpened?

Have you recently purchased a lawn mower? If so, you may be wondering if you can start mowing your grass immediately, or do brand new lawn mower blades need to be sharpened before you mow?

In this article I’ll answer that question, and I’ll also discuss things to look for when mowing that may mean that the blades are dull. I’ll also briefly explain how to sharpen the blades of your mower (including whether you should do it yourself or hire a pro).

Finally, I’ll tell you whether it makes more sense to sharpen old blades or just go ahead and buy new ones when your lawn mower blades become worn out.

Let’s get into it!

Trust and Accuracy Information

This article was last updated on by Lawn Chick Owner Sarah Jameson
Article content reviewed for accuracy by Horticulturist Arthur Davidson, A.S.

Why is it Important to Have Sharp Blades on Your Lawnmower?

Dull lawn mower blades can lead to a variety of problems, such as a clogged mower, improperly and inadequately cut grass, grass trailings, and more.

Do New Lawn Mower Blades Need to Be Sharpened?

If your lawn mower is brand new, then there won’t be any need to sharpen the blade. During the manufacturing process, mower blades are always sharpened, and new mowers come with sharp blades from the factory.

Do New Lawn Mower Blades Need to Be Sharpened?

Problems When You Mow with Dull Blades

If you use a lawn mower that has dull blades, then you will end up with grass that has jagged tears on the tips. After a while, the tips will take on an unattractive yellowish hue.

When you ensure that your mower has adequately sharpened blades, you will achieve a clean cut and this is necessary for the grass to stay in a healthy state.

It’s also better for your mower’s engine.

Using inadequately sharpened mower blades can lead to mowing injury of your lawn and this can lead to a ragged lawn with a potentially brownish hue.

More importantly, ragged ends on grass from dull blades can lead to your lawn being more susceptible to disease, which is something that many homeowners don’t realize.

The Importance of Mowing Regularly

Remember to mow your lawn on a regular basis using a mower with appropriately sharp blades.

Even if mower blades are sharp enough, not mowing regularly can also lead to similar problems to those caused by blunt blades. is reader supported. If you make a purchase after clicking a link, I may earn a commission at no additional cost to you.

How Often Do Brand New Lawn Mower Blades Need to be Sharpened?

As mentioned above, brand new lawn mower blades do not need to be sharpened because they are always sharpened during manufacturing.

However, lawn mower blades do generally need to be sharpened at the beginning of each new season.

Freshly Mowed Grass

At the very least, your mower blades will benefit from being sharpened once at the beginning of each year.

If you have a lot of sticks and stones in your lawn or if your green space is very large, then you might have to sharpen your blades more frequently.

Be careful not to set the cutting deck of your mower too low. Doing so can lead to the blade being severely impacted by objects in your yard. As a result, you’ll have to sharpen more often.

How to Sharpen Your Mower Blade

Many homeowners prefer to hire a professional to sharpen the blades of their lawn mowers. However, if you’d like, you can do it yourself.

Check out your mower’s product manual for specific instructions on how to sharpen the blade. It will tell you how thick you should keep the cutting edge for best performance.

A Dull Lawn Mower Blade that Needs to be Sharpened
A dull lawn mower blade that needs to be sharpened

If you no longer have the manual, you can often find digital versions online with a quick Google search.

Alternatively, you can simply try using a grinding wheel to smooth out the edge. Be careful not to get carried away with this. Don’t ruin the shape. And ensure that the blade is properly balanced before you’re finished.

Tools for Sharpening Your Mower Blade

You can buy a sharpening tool on Amazon or elsewhere to sharpen your own mower blades, but be sure to buy a blade balancer as well. The issue most people run into when sharpening their own mower blades is that the blade loses its balance and that causes the mower to work poorly.

Maintaining appropriate safety standards is paramount when sharpening blades.

Wear eye protection and gloves while you sharpen, and make sure to disconnect the spark plug of your mower before you begin working on it.

It’s also a good idea to always have an extra set of replacement blades available.

How Often Should You Replace Your Mower Blade?

Regardless of how much you sharpen your mower blade, I recommend that most homeowners replace their mower blades every 4-5 seasons.

Once a year is a rule many homeowners abide by, but I usually sharpen my blades annually and replace my blades with new ones from the manufacturer every 5 years.

The condition of the blade will determine exactly how frequently this will need to be done for your mower. A yard with stones, large sticks, and other debris could lead to greater wear. This may mean that you’ll have to replace the blade more often.

Big Lawn with Trees at Sunrise

The length of time it takes to mow your lawn will also impact how often a blade needs to be replaced.

You will need to use a torque wrench when installing your new mower blade, and always wear gloves and safety gear.

How Sharp Should a Mower Blade Be?

Remember that the mower blade doesn’t need to be as sharp as a knife.

The face should not have any gouges and the blade needs to be bevelled appropriately. In order to take a look at the blade, put your mower on its side. Ensure that the carburetor side is facing upward. This is essential to prevent potential gas spills.

If you notice any significant gouges or indentations on the blade, then the blade probably needs sharpening.

Another good way to tell is to inspect your grass after you mow. If the ends of the grass blades are cut well your blade is fine. If your grass blades have rough, ragged edges, then it’s time to sharpen.

Ends of Grass Blades

It may be possible to sharpen the blade without removing it. But that’s only true if the blade is not severely worn or damaged. But it’s usually best to remove the blade.

Sharpening the blade without removing it can lead to the possibility of making it unbalanced, which is the worst thing you can do to a mower blade. An unbalanced mower blade will make the mower vibrate when it is in use.

It’s Important to Properly Maintain Brand New Lawn Mower Blades

While you don’t have to sharpen brand new lawn mower blades, it is important to properly maintain your mower’s blades and keep them sharp.

Choosing the right mower and maintaining it each year will help your mower perform well for years.

And remember – if you’re intimidated by the idea of sharpening your mower blades when the start to get dull, you can order new ones online from Amazon, or your local Home Depot might carry them.

Replacing your blades with new ones that are sharpened to the manufacturer’s standard will ensure your mower performs well.

At Lawn Chick, I am committed to publishing accurate, useful, and trustworthy resources for my readers. As part of this commitment, I’ve invited subject matter experts to review our articles for accuracy. I invite you to read our editorial policy and publishing standards which outlines in detail how every article on this site is sourced, edited, fact-checked, and vetted.



Sarah Jameson’s blog, Lawn Chick, is read by over 2 million homeowners each year and she is regularly cited as an expert source of lawn care knowledge by major publications. Her goal is to meet you where you are, and help you achieve a yard you’ll be proud of. Ready to take the next step toward improving your lawn? Grab her free lawn care cheat-sheet: What to Do When - Take the Guesswork Out of Lawn Care, or upgrade your garage by browsing her favorite DIY lawn care products.

6 thoughts on “Do Brand New Lawn Mower Blades Need to be Sharpened?

  1. Bob Grayson

    When you said mower blades should not be as sharp as a knife was the key statement I was looking for. I’ve seen blades get sharpened by “professionals” and they are like a razor edge. I didn’t think that was right but I trusted them. Thanks for clarifying that.

    • Typically every blade that comes from the factory has an edge and doesn’t need to be sharpened out of the box. It’s a good idea to check the balance on them before installing, and of course if you notice really rough tips to your grass blades you’ll want to sharpen it yourself.

  2. Ross

    I bought a new blade for my MTD side discharge mower. Correct Model number, etc. It came black and shiny with a very dull rounded edge to the blade. Do I need to have this sharpened before I use it or is it supposed to be like this?


    • Hey, Ross!

      Great question. These days a lot of replacement blades will come from the manufacturer in the condition you describe here. Often this is because the manufacturer doesn’t want people cutting themselves during the install, which can be dangerous with a razor-sharp blade. Because of the speed at which most mower blades spin, often the blade will work fine as-is out of the box, and even if it feels dull to you, they’ll perform once installed. The best thing to do may be to install it and take it for a test drive on the lawn, gauging for yourself how it feels, and then looking at the tips of your grass blades to see if they are cut cleanly or ragged and torn.

      My guess is that it will probably work ok as-is, but for the cleanest of cuts you’ll want to sharpen it, and do that at least once annually going forward. You can do this yourself with an angle grinder, and a small balancing kit that you can buy locally at a hardware store for around $10. It’s important that as you sharpen the blade you keep it in balance so that there’s no wobble as it spins in the mower (that will happen if one side is heavier than the other because the metal was not taken off evenly on both ends of the mower blade).

      Hope this helps!

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