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How to Sharpen Lawn Mower Blades Fast

02/26/23
Patio, Lawn & Garden
Keep your lawn looking great with sharp lawn mower blades! This easy guide will show you how to sharpen them properly.

Do you want to keep your lawn looking green and groomed? Of course, you do! That's why it is essential to learn how to sharpen lawn mower blades. 

With a few simple tools and a bit of elbow grease, you can easily maintain the sharp blade necessary to cut grass efficiently and effectively - but where do you start? 

Our experts will provide step-by-step instructions on what needs to be done when sharpening your lawn mower blades

So let's get started on how to keep your grass greener. 

Why It’s Important to Sharpen Your Lawn Mower Blades

Sharpening your lawn mower blades is essential for maintaining a healthy and attractive lawn. Here are some reasons why it's important to sharpen your lawn mower blade regularly:

  1. Clean cuts: A sharp blade cuts the grass cleanly and evenly, which promotes a healthy lawn. A dull blade, on the other hand, tears and shreds the grass, making it more susceptible to disease and pests.

  2. Improve lawn appearance: A sharp blade creates a cleaner, neater appearance to the lawn after mowing, as opposed to the ragged and uneven cut of a dull blade.

  3. Reduce mowing time: A sharp blade cuts grass faster and more efficiently, reducing the amount of time you need to spend mowing your lawn.

  4. Save fuel: When a mower blade is dull, it requires more power to cut the grass, which can increase fuel consumption and the cost of mowing your lawn.

  5. Extend blade life: Regularly sharpening the blades can extend their lifespan, saving you money in the long run as you won't need to replace the blades as frequently.

Sharpening your lawn mower blades is critical for maintaining a healthy and attractive lawn while saving time and money in the long run. It's recommended to sharpen your blades at least once a year or more often, depending on how frequently you mower your lawn.  

Remove and Clean the Blade

Removing and cleaning the blade before sharpening it is crucial to ensure the blades work effectively. Here's how to remove and clean the blades: 

  1. Safety first: Before removing the blade, turn off the lawn mower and disconnect the spark plug wire to prevent accidental start-ups.

  2. Remove the blade: Use a wrench or socket to remove the nut that holds the blade in place. Be careful not to damage the blade or the lawn mower while removing it.

  3. Clean the blade: Use a wire brush or a metal scraper to remove any debris or built-up grass clippings from the blade. Wear gloves to avoid injury from the sharp edges of the blade.

  4. Inspect the blade: Look for any cracks, bends, or other damage that may require blade replacement. If the blade is damaged, do not attempt to sharpen it.


How to Sharpen the Lawn Mower Blade

There are 3 ways to sharpen your lawn mower blade:
By hand, by using drill-powered blade sharpener or by using an angle grinder.

Safety first - Before you start, turn off the lawn mower and unplug it or remove the spark plug to prevent accidental starting. Wear gloves and eye protection.

Sharpening a lawn mower blade by hand can be done using a metal file or a sharpening stone. Here's how to do it:

  1. Remove the blade from the lawn mower. Use a wrench to loosen and remove the bolts that secure the blade to the mower. Keep in mind the direction of the blade before you remove it so you can put it back on correctly.

  2. Secure the blade in a vise or clamp it to a workbench.

  3. Use a metal file or sharpening stone to sharpen the blade. Hold the file or stone at the original angle of the blade's bevel and run it along the edge of the blade, starting at one end and working toward the other end. Maintain the original angle of the blade's bevel as you work.

  4. Work on each side of the blade equally to maintain the blade balance. 

  5. When the blade is sharp and balanced, reinstall it on the mower. Make sure to tighten the bolts to the manufacturer's recommended torque specifications.

  6. Test the mower to ensure the blade is working properly and cutting evenly.

Here are the steps for sharpening lawn blade with a drill-powered blade sharpener:

  1. Remove the blade from the lawn mower. Use a wrench to loosen and remove the bolts that secure the blade to the mower. Take note of the orientation of the blade before you remove it so you can put it back the way it was.

  2. Secure the lawnmower blade in a vise or clamp it to a workbench.

  3. Attach the drill-powered blade sharpener to a power drill, following the manufacturer's instructions.

  4. Hold the blade steady with one hand and run the drill-powered blade sharpener along the edge of the blade, starting at one end and working toward the other side. Keep the original angle of the blade as you work.

  5. Work on each side of the blade equally to maintain balance. 

  6. After the blade is sharp and balanced, place it back on the mower. Make sure to tighten the bolts to the manufacturer's recommended torque specifications.

  7. Test the mower to ensure the blade is working properly and cutting evenly.


Keep in mind you have to carefully follow the manufacturer's instructions, as improper use could damage the blade or the drill.

Follow these steps to sharpen mower blade with an angle grinder: 

  1. Remove the lawn mower blade from the mower deck. If you're not sure how to do this, check the manufacturer manual for the specific lawn mower model.

  2. Clamp the lawn mower blade in a vise or securely hold it with a pair of pliers to prevent it from moving while you sharpen it.

  3. Use a metal grinding wheel on the angle grinder to sharpen the blade. Make sure the angle grinder is turned off before attaching the grinding wheel.

  4. Hold the angle grinder with both hands and position it at a 45-degree angle to the cutting edge of the blade.

  5. Slowly move the angle grinder across the blade, keeping the angle and pressure consistent throughout the sharpening process. Try to remove as little material as possible from the blade to extend its life.

  6. Take breaks every few minutes to check the blade's progress and ensure a consistent angle.

  7. Once the blade is sharp, use a file or honing stone to remove any burrs or rough edges from the blade's cutting edge.

  8. Finally, reattach the blade to the lawn mower and reconnect the spark plug wire.

Check the Blade Balance

A balanced blade can help ensure a smooth cut and reduce the risk of damage to the mower or injury when you are operating it. 

Check the blade balance by observing which side of the blade dips down toward the ground. If one side of the blade is heavier than the other, it will cause the blade to be unbalanced.

Mark the heavy side of the blade with a piece of tape or marker and remove a small amount of material from the heavy side of the blade. 
Be careful not to remove too much material, as this can cause the blade to become unbalanced in the opposite direction.

After you adjust the blade, rehang it on the straight object to check the balance again. Repeat the process until the blade is balanced and once done, reinstall the lawn mower. 

Reinstall the Blade

Here's how to reinstall the blade for your mower lawn:

  • Gently lay the mower on its side so you can access the underneath of the deck where your blade is located. You may need to unscrew multiple nuts if it’s necessary for easy access. 

  • Locate the torque arm, which secures the blade in place, and make note of its size before loosening it with an adjustable wrench (or other tools). Take caution not to remove more bolts or nuts than needed since some parts may be difficult to replace once they're removed. 

  • Place the sharpen mower blade on top of the torque arm made, make sure it fits by using a ruler or measuring tape. Secure it with screw nuts and don't over tighten it. Once attached, use the hand adjusting tool (if available) until there's no movement visible – then double-check for alignment. Again, make sure everything lines up correctly within each side panel/housing bracket area.

  • Reattach the mower deck covers back onto the machine being mindful not to flow any wiring connectors through while doing so because they must remain intact during operation mode. Ensure they stay connected at all times. Then re-tighten any additional screws needed firmly into place without over tightening them again either.

How to Maintain Your Mower Blade

In order to keep your mower blade in top condition and cut grass at its best, it’s important to sharpen, balance, and store the blade properly. 

Sharpening your mower blade is necessary for it to function optimally. 
It’s also important that your mower blade is balanced. An unbalanced mower blade can cause uneven grass cutting as well as cause vibration while in use. 

Finally, store your mower blades when not in use. Spread a light coating of oil on both sides so that rust doesn't form. Wrap it in wax paper before storing it away safely from children and pets in a cool dry location. 

FAQs

What tools do I need to sharpen a lawn mower blade?

Some of the basic tools you’ll need are:

a vice or clamp to hold the mower blade securely while sharpening; 
a hammer or mallet; and files, stones, grinders, and/or sharpeners that are specifically designed for use on mower blades. 

You’ll need a file with different angles -an 8-inch flat file will do the trick. Choose single-cut mill files over double-cut options since single-cut can work faster and smoother without leaving grooves in the metal surface as double-cuts can do.

Another option is to invest in an angle grinder that spins at higher speeds than average drill motors and provides more consistent results with less effort on your part.

Diamond stones are perfect for getting into tight areas and removing large amounts of material quickly, while still providing enough control to prevent damage from overheating or creating too small of an edge angle on your blade. 

Finally, all-inclusive kits may include other items such as knives & shears sharpener stones; turbine handpieces; spikes & clamps; guide blocks & plates sandpaper sheets/discs, etc.
They can come in handy if there are issues beyond simple grinding edges that require touching up details. 

How to sharpen a lawnmower blade with a whetstone

To sharpen a lawnmower blade with a whetstone, first, you need to assemble all of the necessary tools: a whetstone, safety goggles, work gloves, a vise or clamp for securing the blade in place, and machine oil. 

Next, you'll want to secure the blade in place so that it won't move as you sharpen it. This can be done by putting it in a vise or clamping it down onto a workbench. Once secured properly, apply some machine oil to both sides of the blade. This will help reduce friction as you sharpen.

Once ready for sharpening, use long strokes (in one direction) along the edge of the blade with moderate pressure on top of the whetstone. 

When finished sharpening both sides, clean off any residual metal filings from the blade by wiping off with either an old rag or paper towel dampened with machine oil or other lubricant and then reassemble onto the mower. 

Finally, run a few tests over the grass to make sure everything looks good before using it regularly again.

How to sharpen an ego lawn mower blade without special tools

Here’s how to sharpen an ego lawn mower blade without tools:

  1. Find a sturdy flat surface such as a workbench or concrete floor to sharpen your blade on. Make sure the surface you use is clean and free of debris before proceeding.

  2. Use a file or grinder, star by filing down any nicks or burrs along each side of your blade until both sides have an even shape. 

  3. Then, move on to sharpening each side using medium to fine-grade sandpaper or wet-dry sandpaper. 

  4. Once both edges are sharpened, reattach your mower blades back onto their housing by reversing the steps you used earlier when taking them off.

  5. When finished, all that’s left is to safely start your engine again and test your newly sharpened blades.

How do I sharpen lawn mower blades with a bench grinder?

Here are the steps to sharpen lawn mower blades with a bench grinder:

  1. Secure the grinding wheel to the grinder and check its guard is in place and functioning. 

  2. Set up the blade to rest firmly on the grinding wheel without wobbling. You should then slowly bring the blade closer to the grinding wheel, making sure it remains steady.

  3. Don't apply too much pressure - just enough for the edge of the blade to make contact with the grinding surface. 

  4. Once you've gone from one side of the blade to the other use a wire brush or steel wool to remove any excess material that has been ground away from your blades' edges. 

  5. Disconnect your bench grinder from the power source and inspect your blades once more before reattaching them back onto your lawn mower's deck. 

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According to our experts, the Greenworks Pro 80V 21" Brushless Cordless Lawn Mower is a powerful and efficient tool to take care of your lawn. 

With two 2.0Ah batteries and a 30-minute rapid charger included, you can mow up to a half acre on a single charge. The brushless motor provides longer life, more power, and quieter operation.

The 21-inch steel deck offers a cutting capacity. The mower is also lightweight and easy to maneuver, with seven cutting height positions to choose from. 

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The SuperHandy String Trimmer Walk Behind 21" Inch Line Cutting Diameter is great for landscaping, lawn care, and brush clearing. 

Our experts find its wide cutting diameter of 21 inches is capable of cutting through thick brush and greenery with ease. The walk-behind design makes it easy to maneuver and operate, while the adjustable handlebar provides comfortable and customizable handling. 

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Airbike Brush Cutter Weed Wacker Weed Eater Edger Lawn Tool (Upgraded Version), Multi-Purpose, Lightweight, for Lawn, Yard, Garden, Shrub Trimming and Pruning (Red Blade Trimmer + 2 Batteries)

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The Airbike Brush Cutter Weed Wacker Weed Eater Edger Lawn Tool is a versatile machinery for trimming and pruning your lawn, yard, or garden. 

According to our experts, this upgraded version features a red blade trimmer, and comes with two batteries, providing longer battery life and uninterrupted work time. 

It is lightweight and easy to handle, and the adjustable handle and head angle make it simple to customize the tool to your needs and preferences. 

The brush cutter is also easy to assemble and disassemble, making it convenient for storage and transportation. 


Conclusion 

In the end, sharpening your lawn mower blades doesn't have to be a difficult task. With the right tools, preparation, and instructions, it can be a straightforward job. 

We hope you will use this guide and learn everything you need about sharpening your lawn mower blades. Our experts are sure the results will be a great functional lawn mower and a greener garden.