How to Sharpen a Lawn Mower Blade With a Grinder- Safest Steps Ever

Do this once a year to extend the life of your lawnmower. It is recommended that you sharpen a lawnmower blade of your lawn at least once a year. To some homeowners. However, that may seem unnecessary. You know How To Sharpen a Lawn Mower Blade With a Grinder.

Even if the blade is a little dull, they will still cut grass, right? Yes, but that’s not the point. The main point is to sharpen a lawnmower.

How To Sharpen A Lawn Mower Blade With A Grinder-Step by Step

Limp blades will roughly rip through the grass. Leaving behind raggedly torn tips on the ends of the individual many grass blades and that can cause the grass to turn brown & leave your lawn more susceptible to disease & pests. Sharp blades on the other hand cut grass quickly & cleanly so the resulting in a neatly trimmed, healthier lawn.

Get Cutting

The best self-propelled lawn mowers. So each year, before the start of the mowing season. Sharpen the blade of your lawnmower and if you regularly scalp the ground and hit rocks, you will need to sharpen it again midway through the season.


Step 1: There are few different ways to sharpen lawn mower blades.Using a bench grinder, hand file, rotary tool, and angle grinder. But here is a quicker, easier, and more accurate method, use a drill and sharpening stone that’s specifically designed for putting or cutting edge back onto dull lawn mower blades.

Step 2: The following instructions explain how to remove the mower blade before sharpening. But depending on the design of your lawnmower, you might be able to sharpen the blade without removing it.

Step 3: This will save a considerable amount of time. Still, I prefer taking the blade off. This allows greater access to cutting edges & permits better visual inspection of any damage to the mower blades, such as stress fractures and excessive wear.

Step 4: sharp blade lets you cut faster than doesn’t bog down the engine and is better for your grass. That’s because of the dull blade tears the grass. Which stresses it and leaves it more susceptible to fungi and many more diseases. Sharpening the blade a double-time per season keeps it cutting smoothly.

Step 5: Sharpen places the blade in a sin. Start from the inside of the blade & file toward the outside. Following the blades cutting edge. Smooth out any rough spots or nicks.

Step 6: The lawnmower blade doesn’t need to be sharp enough to shave with. If it is too sharp, it will dull quickly. The rule of thumb is that it should be as sharp as a knife.

Step 7: Once you have filed both ends and make sure the blade is balanced by hanging it horizontally on a nail. If one side dips, it is heavier than the other side. File a little more off that side until it is balanced.

Mower Tips

When removing the blade lift the mower so the air filter is facing up to prevent gas from dripping into the filter. Mark the blade with spray paint and a piece of tape before removing it.

So you will know which way to reinstall it. Be sure to remove the spark plug wire & tape it back so the engine does not accidentally start if you happen to turn the blade when removing it also.

Eight Steps To Sharper Blades


Disconnect the ignition wire from a spark plug, If it’s a cordless mower, remove the battery pack. That will eliminate any chance of the engine accidentally starting up. While you are working on the mower. Also drain the gas tank so it won’t spill any fuel, while you remove the lawnmower blades.


The mower onto it is the side to expose the retaining nut and bolt that secures the blade to the underside of the mower. To keep the blade from turning, wedge a short wood block between the end of the blade and the surface of the mowing deck.

Next, use a large ratcheting wrench and socket to loosen the nut and bolt. If the fastener is rusted on, apply some penetrating oil such as Liquid Wrench. Wait 10 minutes and so. Try again and to increase leverage when loosening a particular stubborn fastener, slip a metal pipe over the wrench handle.


After removing the retaining nut and bolt pull off the mower blade. Making note of which side of the blade faces downward. The blade must get bolted back on in the same addiction.


With the blade removed take a minute & shave clean the underside of the mowing deck with a narrow-blade putty knife. Remove all caked-on grass, mud, leaves & other debris. Also, clean both sides of the lawnmower blade by first spraying with penetrating oil & then scrubbing with a stiff-bristle brush.


Lawnmower blades typically have a cutting edge on each end. Which are positioned on opposite sides of the blade? Each cutting edge is only about 3 and 4 inches long. It does not extend the length of the blade. Clamp the blade in a vice at an angle with one of its cutting edge facing up.


Next, you will use a drill-powered blade sharpener. It consists of around abrasive stone, sharpening guide, and ¼” diameter steel shank. The stone has a beveled surface that grinds the ideal cutting angle into the blade.


check the sharpening stone into a drill. Put on some safety for glass. The trigger to run the drill at full speed. Slip the circling sharpener over the edge of the blade.

Be sure the dull cutting edge faces the beveled side of the stone and the flat surface of the guide is against the rear of the lawnmower blade. Slowly move the stone back & forth along the cutting terminal using medium pressure.

After four and five back and forth strokes, stop & check the sharpness of the lawnmower blade. If necessary, repeat until all nicks & chips have been ground off & the blade is sharp. Remove the blade from the vise & rotate it to sharpen the opposite cutting terminal.


Once both cutting edge have been sharpened. There is one more important step that balances the blade. Sharpening can occasionally remove more humor from one end of the blade than the other resulting in an unbalanced blade.

Mowing with a lawn blade that is out of balance will cause excessive quavering. Which can damage the motor & put illogical stress on the lawnmower?

One way to determine, if a lawnmower blade is properly balanced is to simply slip. The blade’s center hole over a nail protruding from a wall. Hold the blade in the horizontal position & let go, If it remains level then it is balanced.
However, if either end rotates down toward vertical. The blade is out of balance, sharpen the heavier end to remove some metal & then retest it.

While the nail in the wall technique does work for more precise results. Use a lawnmower blade balancer a multi-tiered, cone-shaped metal fixture.

Place the balancer on a flat surface then set the blade on top. The pointed stepped designed accepts blades with various diameter center holes.

If the balance is balanced it will stay level. If not it will list to one side and the other indicating which end is heavy.Needs additional sharpening.


Once the blade has been sharpened and balanced. Place it back onto the mower in the original position. Use the wrench to snugly tighten up the retaining nut and bolt. Re-attach the ignition wire, fill the gas tank & take your newly sharpened lawn mower out for a test run.

You could sharpen your lawnmower blade with a grinder. A rotary tool and a bench grinder but we will show you how to do the job with an angle grinder. It is fast and easy to sharpen your lawnmower blade. You will need a socket and distort to fit the blade nut.

Sharpen Ways

There are few different ways to sharpen lawn mower blades. Including using a bench grinder, hand file, rotary tool, and angle mower grinder. But depending on the design of your mower then you will be able to sharpen the blade without removing it. Which will save a considerable amount of time?

How Do You Sharpen a Manual Mower Blade Without Removing It?

To sharpen your tool with a lapping kit, attach the handle to the driving gear of your circulation mower & use a paintbrush to apply the sharpening compound to all of the lawnmower blades. Then you just need to harsh the reel backward so that the mower blades scrape each other down, restoring their sharp edge.


Keeping your lawn mower blades sharp in a grinder with good condition helps to keep your lawn in good condition to How To Sharpen a Lawn Mower Blade With a Grinder.

Not only will your lawn look much nicer but also your lawn will be healthier. Bill’s Outdoor Power is here for you if you need help and a new part. For everyone that is not comfortable doing this yourself. Our service department is ready to help so your lawn keeps looking good.