How to Sharpen Lawn Mower Blades Without Removing?

A pristine lawn requires sharp lawn mower blades. And yours are getting dull. But the thought of having to remove the blades to sharpen them or sending them over to be sharpened by a professional doesn’t amuse you.

I know the feeling, so I’m going to teach you how to sharpen lawn mower blades without removing them. Follow all the steps described below, and you’ll get the job done in no time.

Lawn Mower Blade Sharpening Safety Tips

Your lawn mower may be off when you’re trying to sharpen the blades, but there’s still a chance of injuring yourself if you don’t take your safety seriously. Basic safety measures you should observe:

  • Put on protective gear. This includes cut-resistant gloves, protective eyewear/goggles, and an apron or overalls.
  • Consider working on a flat surface for improved stability and access to the blades

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How to Sharpen Lawn Mower Blades Without Removing

The visual appeal and health of your lawn speak volumes about the state of your lawn mower. A lawn mower with blunt blades leaves your lawn vulnerable to numerous risks. Pests and diseases will likely develop on your lawn and bring a snowball effect, leading to potentially significant issues.

Owning a lawn mower comes with the acceptance that you have to do a bit of maintenance from time to time. Part of maintaining a lawn mower means learning how to sharpen the blades. Removing the blades is not always the easiest option, and without some level of knowledge or experience, the assembling and disassembling of the blade can be a hassle. So let’s get into the steps by step guide on how to sharpen your lawn mower blades without removing them.

Sharpening Lawn Mower Blades Without Removing

Sharpening your lawn mower isn’t as complicated as it seems. These 7 simple steps will make it look like a walk in the park.

Equipment List

Sharpening your lawn mower is only possible if you have the right set of tools and equipment. They include

  1. A rotary sharpening tool, grinder, or flat file
  2. A bucket of water
  3. Two blocks of wood
  4. Oil/lubricant or cleaner
  5. Steel wire or stiff-bristled brush
  6. Shoe rug

Above are the essential tools and equipment you’ll need to complete the task. Feel free to add whatever else makes your work easier and more convenient.

  1. Disconnect Power Supply

The standard lawn mower blade spins at a speed of between 3mph and 7 mph. For a commercial-grade lawn mower that will go up to between 7mph and 13mph  If you work on your lawn mower without disconnecting the power supply, you risk injuring yourself severely.

Basic safety thus dictates that you turn off the power connection to the machine before sharpening the blades.

If you have a gas-powered lawn mower, disconnect the spark plug to avoid starting the lawn mower by surprise. Alternatively, disconnect the battery by unplugging the power cord if yours is a battery-powered lawn mower.

  1. Empty Gas Tank

This step doesn’t apply to all lawnmowers. However, if yours is a gas-powered machine, you must drain the tank before beginning the sharpening process. Alternatively, you may seal the gas cap to ensure no chance of accidental gas leaks when you tip over the lawn mower to position it correctly for sharpening.

  1. Tip Lawn Mower on Side

Tipping your lawn mower on the side helps expose the blades in readiness for cleaning and sharpening. Check to see if any loose parts need tightening. Also, watch the gas tank to see if there are any gas spills or fumes.

  1. Stabilize Lawn Mower

Use stable wooden blocks to keep the machine stable during the process. When you want to sharpen your lawn mower blades without removing them, ensure the machine won’t move while you’re working. A wooden block keeps the machine from budging no matter how vigorously you are when sharpening the blades.  

The last thing you want is a damaged lawn mower that slipped or rolled away or an injury that would have been prevented if you secured your lawn mower properly during the sharpening process.

  1. Clean Mower Deck and Blade

A lawn mower used constantly collects a lot of debris in the undercarriage. Before sharpening the blades, you want to make sure you can see where they are. Once the lawn mower is securely placed, use a hard bristled brush and some water to loosen the dirt.

Keep brushing until all the debris is gone and the blunt blade is clearly visible. Plus, you may be surprised to learn that the accumulated debris keeps your lawn mower from working correctly even when the blades are sharp enough.

Grass clippings, twigs, mud, and leaves collect at the bottom of the lawn mower over time. If you don’t remove the dirt regularly, your lawn mower may not work desirably.

Make sure the blades and undercarriage are completely dry before sharpening. Note that almost the entire lawn mower is made of metal. While water helps a great deal during cleaning, it can promote rusting if you do not thoroughly dry the machine.

  1. Clamp Blade

Not all lawn mowers support this feature, but clamping your lawn mower blades is imperative when you want to do a thorough job. The blades on the lawn mower move in circular motions during operation. Clamps hold the blade in place, keeping it from turning when you sharpen the edges.

An excellent alternative is locking pliers or a wood block to hold the blade in one position if clamps are without reach.

It’s not advisable to hold the blade with one hand while sharpening it with the other. While this technique works for most people, it puts you at risk of severely injuring yourself should you lose your grip. This is especially true when using an angle grinder or drill to sharpen the blades.

  1. Use a Grinder or File to Sharpen the Blade

A lawn mower blade is divided into two halves with each half having a cutting edge that requires regular sharpening. As you are sharpening the lawn mower blade without removing it, you’ll only sharpen the edge of the visible and reachable blade.

Using a grinder or a file can get your lawn mower working correctly. Using a file is a lot of manual work for which many have no time or patience. However, an electric-powered grinder or a rotary tool works faster and produces better results.

Be sure to slant the grinder at an angle to get the blade as sharp as you want. It will take about five to ten minutes to sharpen each side of the blade. If you are using a rotary tool, set it at an angle of 45 degrees for the most precise results.

Once you’re done sharpening the blades, use a shoe rag or thick cloth to clean metal shavings from the freshly sharpened blade. After that, turn the lawn mower right side up and reconnect it to the power source. If necessary, fill up the gas tank too. Take it outside and give the mower a try.

Only Sharpen the Blade on One Side

Is it commendable to sharpen both sides of the lawn mower blade? Worry not; sharpening one side of the blade works just as fine even when you can’t access the inner side of the blade if your lawn mower is fitted with double-sided bevel blades.

How To Tell if Your Mower Blade Needs Replacing

You can only sharpen your lawn mower blades one too many times before they need replacing. But how can you tell whether the blades need sharpening or replacing? You will use your lawn mower for years before the blades are worn enough to warrant replacing.

Consult a professional to find out whether or not you should have your blades replaced with new ones. Some of the tell-tale signs indicating you need a blade replacement on your mower include

  • Your lawn mower is several years old
  • The blades still feel dull after sharpening
  • The lawn mower cuts grass unevenly even after sharpening
  • The blade is bent or damaged
  • You see torn grass on your lawn right after mowing

How to Sharpen Lawn Mower Blades Without Removing: Important Tips

Being on top of the state of the blades is important if you care about the good maintenance of your lawn mower. I’ve gathered below some extra tips related to this topic that I think can be useful.

  • Regularly check on your blades. Failure to check whether or not your blades are sharp could cause you more stress than necessary. By regularly examining the blades, you can sharpen them as soon as they become dull. 
  • Notched blades are not useless. Most users tend to throw away notched blades. However, notched blades, once appropriately sharpened, are pretty usable.
  • Ensure the blades are balanced correctly. Unbalanced blades do not work correctly and make annoying noises when your lawn mower is on. Blunt blades are the number one culprit behind improperly balanced blades.
  • Know when it’s time to get new blades. If the blades are notched all over, unbalanced, or have suffered severe damage, it might be time for a switch. Even after repair, such blades are too damaged to work desirably on your lawn.

When to Sharpen Your Lawnmower Blades Without Removing

There are a variety of factors that inform whether or not you should sharpen your lawn mower blades. Check out the details below.


Some people prefer their lawn mower blades as sharp as a knife without the slightest hint of dullness. Others do not mind a slightly dull blade that does its job well.

While preference is an excellent consideration, you can’t get too carried away. When you sharpen your mower blades too often, you may compromise the health of the blade. A good blade isn’t thinned or weak due to over-sharpening and other external factors. It is sturdy and tough enough to maneuver any lawn, irrespective of size.

Frequency of Use

How often you sharpen your blades is mainly determined by how many times you mow your lawn within a specific period. Say you mow your lawn once every week on one property and use a different mower to mow the lawn once every month on a separate property. The lawn mower blades on the first property will wear out faster than the other machine that’s not used often.

The general rule of thumb dictates that you sharpen your mower blades at least once every twenty hours. Thus, if it takes an hour to mow your lawn, consider sharpening the mower blades after twenty uses.

Lawn Mower Age and Condition

How old is your lawn mower? Is it in good working condition? The age and condition of your lawn mower can affect how well the blades work. It’s safe to say that a newer lawn mower that’s serviced frequently won’t need as much sharpening as an older machine that’s poorly maintained.

Before mowing your lawn, collect garden debris, hard objects, rocks, and other unwanted materials that may compromise the well-being of your machine during mowing. It’s a simple routine that increases the efficiency of your lawn mower and extends the life of the mower blades.

Frequently Asked Questions: FAQs

Here are the frequently asked questions about lawn mower blades sharpening without removing them.

How to Sharpen Lawn Mower Blades Without Removing: Bottom Line

The hustle of unscrewing your lawn mower blade from the undercarriage can be tedious and uncertain, especially if you’re not a handy person. While still attached, sharpening a lawn mower blade saves you plenty of inconveniences and gets the job done. Above is all you need to know about sharpening lawn mower blades without removing plus essential tips.