The foundation of a beautiful lawn is an immaculate cut. But did you know that proper care for your mower’s blades pays huge dividends for the health of your grass? Follow along in this episode of Backyard Smart to get the lowdown on how to sharpen mower blades, so you can keep your backyard life green and pristine.
Why Sharpening Mower Blades Matters
Properly sharpened blades deliver a crisp, clean cut. The benefits of a properly sharpened blade extend to the health of your grass, too. A dull mower blade leaves a ragged cut, which isn’t only unsightly but can be a danger to your lawn. A dull or damaged blade rips your grass, inviting a whole host of lawn pests and diseases to take root. And leaving your yard with an ugly yellow-brown hue.
How Often Should You Sharpen Mower Blades?
Sharpening frequency depends on how you use your mower and how old it is. Here’s a breakdown:
- Before the first mow of the season: To start cutting season off on the right foot, you should always sharpen your blades before the first mow of the year.
- New mowers: Sharpen for the first time between 8 and 25 hours of use to establish the proper edge on a new blade.
- Residential use: Once or twice per season is typically sufficient for personal-use mowers, though larger lawns may require a third sharpening.
- Commercial use: Weekly to bi-weekly sharpening is standard for professional mowing operations to maintain consistent cut quality.
- Pro tip: A quick sharpen after every mow—rather than waiting until blades are visibly dull—can extend blade lifespan up to 10 times longer compared to blades sharpened irregularly.
How to Tell When Your Mower Blades Need Sharpening
Ultimately, the best way of determining when to sharpen mower blades is through regular cleaning. This gives you the opportunity to examine your blades for any nicks, dents, improper balancing, and other signs of damage. And, to quickly tell if your blade is properly balanced, just look at how the grass is clumping. If it’s thicker on one half of the blade than the other, then it’s not balanced and needs a little work.
How to Balance and Sharpen Mower Blades
What You’ll Need:
- Work gloves and eye protection
- Putty knife
- Angle grinder or bench grinder
Step 1: Clean the Blade
Before sharpening, use a putty knife to scrape off any built-up grass, debris, and residue. A clean blade is easier to sharpen evenly, reduces airborne dust during grinding, and lets you clearly see when you’ve achieved the right edge.
Step 2: Sharpen at the Correct Angle
Then, take it to an angle or bench grinder and get to work. Hold a 27° to 30° angle and take your time. Make sure not to overdo it—you don’t need a razor-sharp edge. Multiple, steady passes are key to a properly sharpened blade. In fact, over-sharpening can be just as detrimental as a dull blade. It takes the temper out and will severely impact the blade’s lifespan by increasing the number of times you’ll have to sharpen it.
Step 3: Check the Balance
To test the balance of your blade, just grab a screwdriver and thread it through the center of the blade. If it leans to one side, then it’s time to make a few more passes until it’s even.
Start with the Right Blades
A beautiful cut starts with the right blades—and that’s where Exmark OEM mower blades come into play. Aftermarket parts companies build blades that are “almost right,” but don’t last nearly as long—or deliver a cut nearly as clean—as the real deal. So, when you order an Exmark blade, you can mow confidently knowing you’ve purchased the right sized blade for your machine.
And, by using Exmark OEM replacement blades—which you can purchase online or from your local dealer—you ensure that you always deliver that signature Exmark cut.
That’s it! Now give your lawn a hand, start sharpening, and boost your blades.
The standard sharpening angle for most mower blades is between 27° and 30°. Maintaining a consistent angle throughout the sharpening process is more important than hitting the exact degree.
A freshly sharpened blade produces a clean, even cut that leaves grass tips intact and green. A dull blade leaves visibly frayed, yellowing grass tips and creates uneven clumping patterns across the lawn.
If the blade has deep gouges, significant bends, cracks, or has been sharpened down to the point where the cutting edge is very thin, it’s time to replace rather than sharpen. A blade that can’t hold an edge after sharpening is also a sign it’s past its useful life.
