Professional Tool Reviews for Pros
You might think lawn mower blade sharpening requires tons of skill. While years of practice will hone your technique, the basic principles to sharpen a blade are rather simple. Our DIY instructions show you how to sharpen a lawn mower blade quickly so you can save money and keep your lawn looking great.
You may think a blade spinning at over 180 mph or more wouldn’t need to be terribly sharp to cut grass. You’d be right. However, a nice sharp blade will slice through grass and allow it to grow in a more healthy manner.
Why does this matter? Because “shredded” grass tips will quickly turn brown, leaving your lawn looking ragged and burnt. The following image helps illustrate this:
For professionals, and people who—quite frankly—just like a nice lawn, having sharp lawnmower blades truly matters for a professional look. This goes triple for species like Fescue which grow more or less straight out of the ground and require frequent cutting.
We know professionals who sharpen their zero turn mower blades every other day.
Many ways exist to sharpen a lawnmower blade. Some of the easiest (and quickest) involve using a grinder. The blades don’t actually need to achieve razor sharpness—they just need to have a decisive cutting edge. It’s this edge that slices through, rather than chops, the grass at high speed.
Of course, grinders come in many sizes and forms. Angle grinders, bench grinders…you name it. If you have one of these tools already, then you may have everything you need to sharpen your lawn mower blades. If not, one of our other solutions might work out—so keep reading.
Aside from the use of a grinder, you can also grab a manual file and get to work. Dedicated blade sharpening systems exist that ensure the right angle and consistency when sharpening these heavy blades.
Regardless of which method you choose to sharpen your mower’s blades, we’ll start with the most common and work our way down.
Using a small angle grinder to sharpen lawn mower blades lets you accomplish the task with minimal time investment or cost. You can pick up an angle grinder for very little money, and the process involves matching the angle of the existing blade edge and simply honing it.
Similar to the process above, using a bench grinder to sharpen lawnmower blades works just as easily. A bench grinder reverses the process. Instead of moving the grinder over the blade—you move the blade across the grinder wheel. Since many bench grinders include an adjustable table, you can often get fantastic and consistent results using this method.
Try not to over-sharpen the blade. Doing so only results in a too-fragile edge that dulls more easily and weakens the blade. You also want to use quick passes to sharpen the blade. Be careful not to heat the steel too much. If you do, you may inadvertently weaken the hardening process that holds the blade’s edge.
Another way to sharpen a lawn mower blade involves the use of a cordless drill and a special bit. You can find these in any number of shapes and sizes. These bits match the natural angle of the lawnmower blade.
One advantage of these types of sharpeners is that you can leave the blade on the mower. Depending on the type of blade and mower, you may get better results by removing the blade first. Still, it does provide a truly quick way to maintain your blade sharpness.
These methods are rather forgiving, however, you should take care to not miss an important step: periodically balancing the blade. After taking off some metal on either side of the blade and achieving a nice edge, you need to ensure the blade still balances evenly.
To do this, hammer a 16D or similar nail into a wall in your shed or shop and hang the blade from its center point. If it stays balanced, you’re all done. if not, mark the heavy side with a Sharpie marker and take some additional metal off that side by continuing to sharpen it. Most of the time, you can keep a blade balanced by staying aware of how many passes you make with a grinder. Still, periodically check the blade balance to ensure you haven’t drifted too far on one side or the other.
Regardless of which grinder method you use, balance the blade periodically to ensure it stays even.
We don’t typically recommend the use of a file when sharpening your lawnmower blades. The process is slow and manual, and the results won’t get you a nicer lawn or a longer blade life. Instead, pick one of the grinder methods above and get to work. If, however, you enjoy using a hand file—by all means, go for it.
If you happen to sharpen mower blades regularly—enough to warrant a faster process—several commercial models do exist to save you time. A newly-created tool from Noracore called the Easy Mower Blade Sharpener (EMBSX) has particular promise. In fact, this tool won a 2019 Pro Tool Innovation Award.
This pneumatic tool drives a die grinder with both a mirror and a camera interface that lets you sharpen the blades on zero-turn mowers without removing them. It takes some finesse and skill to use, so it’s not for everyone. You also need to watch that you don’t sharpen one side more than another or you risk unbalancing the blades.
No matter which method you choose to sharpen a lawnmower blade, please be careful to wear proper personal protective equipment (PPE) to protect your eyes, hands, and ears. Grinding mower blades takes little effort and we find it a great entry-level task almost anyone can handle. Still, taking proper safety precautions guards against accidents.
Let us know what you think in the comments below. Do you have a preferred method for sharpening lawnmower blades? Which method works most consistently in your experience? We’d love to hear from you.
When he's not playing with the latest power tool, Clint DeBoer enjoys life as a husband, father, and avid reader—especially the Bible. He loves Jesus, has a degree in recording engineering, and has been involved in multimedia and/or online publishing in one form or another since 1992.
Clint’s career has covered nearly the entire realm of audio and video production. After graduating at the top of his class with an Associates Degree in Recording Engineering, he began working for the famed Soundelux studios in 1994, one of the largest post-production companies specializing in audio for feature films & television. Working on a myriad of feature films, Clint honed his skills as a dialogue editor, foley editor, and sound designer. Years later, he moved into the expanding area of video editing, where he served as the company’s senior AVID video editor for three years.
Working for such clients as Universal Pictures, Hollywood Pictures, Paramount Home Entertainment, NASA, Universal Studios, Planet Hollywood, SEGA, NASCAR, and others, Clint DeBoer dealt extensively with client management as well as film & video editing, color correction, and digital video & MPEG compression. He also carries several THX certifications (Technician I and II, THX Video), and is ISF Level II Certified.
After founding the CD Media, Inc. publishing company in 1996, he went on to help start or grow several successful online publications, including Audioholics (as Editor-in-Chief for 12 years), Audiogurus, and AV Gadgets. In 2008, Clint founded Pro Tool Reviews followed by the landscape and outdoor power equipment-focused OPE Reviews in 2017. He also heads up the Pro Tool Innovation Awards, an annual awards program honoring innovative tools and accessories across the trades.
Crediting God and his excellent staff for the success of what is now the largest power tool review publication in the industry, Clint DeBoer hopes to see continued growth for the company as it rapidly expands its reach. Pro Tool Reviews critically reviews hundreds of hand tools, power tools, and accessories each year to help inform users about the best and newest products in the industry. Reaching everyone from the construction industry professional and tradesman to the serious DIYer, Pro Tool Reviews helps tool consumers shop better, work smarter, and stay aware of what tools and products can help put them at the top of their game.
Over the past few months, we’ve been surveying our audience to see who makes the best tools. The answer, of […]
Switching from Gas to Battery is Easier with the Latest Generation of Battery-Powered String Trimmers Even if you’re not quite […]
Boy, did we open a can of worms when we started searching and testing to determine the best battery-powered chainsaw […]
So this year I finally decided to hack our Christmas tree stand so I could use a power tool to […]
Don’t knock the file if you obviously don’t know how to use one. I second the comment about taking the blade off to balance it then mentioning a device which sharpens the blade on the mower without removing it to check for balance.
After stressing how important balancing the sharpened blade no matter which method one chooses to use. You go on to tell us about the EMBSX Easy Lawn Mower Blade Sharpener winning a innovation award for the ability to sharpen Zero Turn Mower blades without removing them! Riddle me this Batman. How does it balance the blade without removing them?!
I use a file all the time and doesn’t take long. I’ve had really good results.
Just read another article that says hand filing is the only method to use…heat from any power grinder causes the blade to lose its temper and became too weak to hold an edge.
Is it better to have the disc rotating off the blade edge or have rotating blade spinning onto edge for sharpening lawnmower blades? I have seen both ways so maybe doesn’t matter much. Thanks.
As an Amazon Associate, we may earn income when you click on an Amazon link. Thanks for helping us do what we love.
See our Privacy Policy and Terms & Conditions.
Pro Tool Reviews is a successful online publication that has been providing tool reviews and industry news since 2008. In today’s world of Internet news and online content, we found that more and more professionals researched a large majority of their major power tool purchases online. That piqued our interest.
There’s one key thing to note about Pro Tool Reviews: We’re all about the professional tool user and tradesman!
Copyright ©2008-2022 Pro Tool Reviews, LLC. All rights reserved.