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Should I Sharpen or Replace My Lawn Mower Blades?

Should I Sharpen or Replace My Lawn Mower Blades?

Lawn Mower Blade Sharpening and Replacement

By  | Lawn Mower Product Expert

For the homeowner or property owner who’s been looking forward to green summer grass, the sight of brown spots on the lawn can be worse than a sudden crop of dandelions.

You might think that your wilted, dried-up lawn needs fertilizer. You might worry that you haven’t given it enough water.

However, if you haven’t been keeping up on your lawn mower maintenance, there’s a chance that dull lawn mower blades are to blame.


You’ll know that you need to sharpen your lawn mower blades when the tips of your grass are brown and ragged. When this happens, your grass becomes less capable of storing water and more susceptible to disease.

Some lawn mower manuals suggest sharpening or replacing blades after every 25 hours of use. Others suggest doing it at least once a year before you first mow.

Either way, how do you know whether it’s better to sharpen or replace them?

If you want to get technical, lawn mower owners have three options for getting their blades sharp:

  • Sharpening the blades themselves
  • Bringing the blades to a sharpening service
  • Replacing the blades

This article is a guide to help you figure out the right answer for you.

 

Why Sharpen Your Own Mower Blades?

Sharp Mower BladeThe biggest advantage of doing your own lawn mower blade sharpening is that it saves you money. All you need are a few pieces of equipment:

  • Safety glasses
  • Safety gloves
  • A flat metal file
  • A vice or another tool to hold the blade in place

If you already have those in your garage, all that the DIY approach will cost you is time.

That being said, sharpening your own blades can be a timesaver. By doing it yourself, you save the time you would have spent driving to a store or searching online for replacement blades. If you’re a homeowner, you could enjoy some free time instead. If you’re a landscaping pro, you can keep to your work schedule.

So, how do you sharpen your own mower blades?

 

Lawn Mower Blade Sharpening: How-To and Tips

Sharpening lawn mower blades can be as easy as securing the blade in a vice and running a metal file along its edge in line with the angle of the bevel.

However, if a picture is worth a thousand words, then a video probably is worth an entire manual.


Once you feel that you know how to sharpen mower blades, there are a few tips to keep in mind that will make the sharpening go quickly and safely:

To sharpen push mower blades, always drain the fuel tank before turning a push mower on its side, and tip it with the carburetor and air filter facing up. Disconnect the spark plug before doing any work on your mower.

Removing a Mower Blade

Use your flat metal file for quick maintenance or if you suspect you might have hit a rock or another object that nicked your blade. Use a disc grinder to restore the bevel’s angle and the blade’s overall sharpness once or twice a season.

Maintenance schedules vary, but every 25 hours of use is a common suggestion as to when you should sharpen mower blades. A good rule of thumb is to look at the tips of your lawn’s grass blades a day or two after mowing. If they look ragged and torn, your blade is dull.

After sharpening, check that your blade is balanced. Look for a nail or a tack sticking out of a wall, and hang your blade on it through the center hole. If the blade tips to one side, that side is too heavy and needs to be filed.

 

Why Use a Sharpening Service?

Your local hardware store might offer blade sharpening services; you also might find blade sharpeners at such gatherings as farmers markets. Having someone else sharpen your blade can be a valuable option:

  • Blades will be properly balanced
  • Tools and equipment are readily available
  • Possibly a cost-effective option

One advantage of using a blade sharpening service is that you know your blade will be properly balanced. An unbalanced mower blade can cause vibrations and jolts that make using your lawn mower dangerous. If this is a concern, bring your blade to a professional who can sharpen it smoothly and evenly.

Reel Mower Sharpening SuppliesA sharpening service is also handy if you don’t have the tools or the space to sharpen blades yourself. This is especially true if you own a riding mower, which requires you to have a mower lift to maintain it properly, or a reel mower, which uses special sharpening kits for reel mower blades.

Finally, even though the cost might be a concern, the price of hiring someone to sharpen your blade is comparable to buying a new blade and, in some cases, might be lower if you can remove the blade yourself and bring it to the sharpening service.

If you use a sharpening service, be sure to follow the same recommended maintenance and sharpening schedule outlined in your mower’s product manual. If nothing else, stick to the “every 25 hours of use” guideline.

 

Why Replace Mower Blades?

Sharpening your blades is a great option for the budget-minded and DIY-minded consumer, but it might not always be the best option.

Damage to Mower BladesThe most important reason to replace your mower blades that they show signs of irreparable damage:

  • Bent mower blade
  • Cracked mower blade
  • Blade worn down too far

However, you don’t have to wait for your blades to be beyond repair to get a replacement set. Having a set of replacement blades on hand is useful if you want to use your blades for different purposes. This is especially true in the case of mulching blades, as mulching grass can create extra wear on regular blades.

Even if you don’t plan on using blades for different purposes, though, you might replace your blades simply because you want a fresh start. Your thinking might be that if you’re going to spend time taking blades off your mower and putting them back on, why not put on blades that will last?

If you choose to follow that route, be sure to replace your blades on the same schedule you would sharpen them. Every 25 hours of use is still an excellent guideline.

 

Why Not Sharpen and Replace Your Blades?

In the end, the most cost-effective option might be a combination of sharpening your blades and buying a replacement set or two.

Mulching BladeSharpen your regular blades on schedule to help them last as long as possible, but have a replacement set on hand in case of sudden damage. If you happen to hit a rock, you won’t have to wait to sharpen your blades before you can continue mowing. Instead, you can make the most of that summer sunshine while it’s available!

Also, even if you don’t purchase a set of specifically designed mulching blades, you still might find it helpful to use one set of blades for regular mowing and another for mulching in the fall. Because mulching reprocesses grass clippings into fine bits, it wears down a blade’s edge. Having one set dedicated to mulching keeps the other set sharp longer.

With your blades sharp and ready to go, you’ll be ready to keep your grass green and neat all season long.

 

 NEXT: The Ultimate Lawn Mower Maintenance Guide