Grass mower blade sharpening. Do You Need To Sharpen New Mower Blades (Beginners Guide To Blades)

Do You Need To Sharpen New Mower Blades (Beginners Guide To Blades)

In this post, we’ll answer beginner questions about lawnmower blades. And also what you must not do when changing your lawnmower blade.

In the future, if you need video help on inspecting, removing, sharpening, balancing, refitting, and torquing your mower blade, check out “Mower blade sharpening video”.

Do I need to sharpen lawn mower blades?

Lawnmower blades need to be sharpened regularly. A dull blade will pull and tear on your grass blades causing jagged tips. The dull blade stresses the grass and the damaged grass tips turn yellow. A sharp blade will cut cleanly which is healthier for the lawn, easier on you and your mower engine.

How often should mower blades be sharpened?

At the very least your mower blade needs to be sharpened at the start of every new season, and more often if your yard is stony or large. Setting your mower cutting deck to the lowest level will cause the blade to impact objects more often and will obviously need more regular sharpening.

Sharpen once per season, at least.

When should I replace my mower blade?

A mower blade should be replaced about every third to the fourth season. But it really does depend on its condition, a mower blade that cuts a small mature yard will last longer. New yards usually have rocks, stones, and debris that impacts the blade causing it to become dull and wear out quickly.

Blade wear – Check out the wear on this blade, this mower was having all kinds of cutting and bagging problems. A New blade solved all.

How do I know if my mower blade needs to be sharpened?

A mower blade doesn’t need to be knife sharp, but the leading edge of the blade does need to be beveled and the face free from gouges. Examine your blade by turning your mower over on its side but always with the carburetor side facing the sky (prevents gas spill).

Wearing a glove, run your finger along the beveled blade. Are there large indentations or gouges? If the answer is yes, then your blade needs to be sharpened.

Can you sharpen a lawn mower blade without removing it?

You can sharpen a mower blade without removing it, so long as it is not badly damaged or worn. The best practice is to remove the blade from the mower, sharpen and then balance it.

Sharpening the blade on the mower runs the risk of unbalancing the blade which will cause the whole mower to vibrate.

Check out “Blade maintenance tools” here, they make the sharpening process a ton easier, or check out the Amazon link below.

Tools.This method is only suitable for relatively new blades. You’ll need a big flat metal file, move the file at 45 degrees with the bevel, and to finish run the file across the rear to clean the burrs. If your blade is heavily damaged or badly worn, this method isn’t suitable.

The “Mower blade sharpening video” covers the whole process both on and off the mower.

Should I sharpen or replace my lawn mower blade?

If your mower blade is more than four years old and has seen average use, then go ahead and replace the blade. Good quality blades aren’t expensive but note you will need a torque wrench to tighten the blade bolt to specifications.

Tightening a mower blade without using a torque wrench runs the risk of the blade coming loose or destroying the engine. I wrote a post about my torque wrench here “Best torque wrench for mower blades”

Unless your blade is in good condition, I’d spring for a new one. They’re not expensive, but you’ll need to buy or borrow a torque wrench.

How tight should mower blades be?

It’s important to tighten your blade to the correct specification. A mower blade may not be as tight as you might expect.

A blade fits on a blade boss (metal block) which is then fitted to the end of the engine’s crankshaft. A blade is designed to slip on the blade boss if the mower blade hits a solid object.

Over-tightening the blade will prevent the blade from slipping on the boss, and will instead bend the crankshaft and destroy the engine.

Check out the video on blade fitting, it covers torquing the blade to specification. You might find the video on using a torque wrench.

Can you sharpen a Mulching blade?

You can sharpen a mulching blade, it is sharpened in the same way as a collecting blade, best results are achieved by removing it before sharpening and balancing.

Which way do mower blades tighten?

A single-blade lawn mower blade bolt will be a right-hand thread. Viewing the mower on its side (carburetor side up). To tighten the bolt – turn clockwise. To loosen the bolt – turn anticlockwise. I wrote a post on a similar subject “How to remove stuck blade bolt”

Which side of the lawn mower blade is up?

All mower blades will have a lifted trailing edge. The lifted edge points upwards, to the underside of the lower body.

This side up

Do lawn mower blades need to be timed?

A single-bladed mower will not need to be timed. A twin-blade walk behind mowers like a Toro or some lawn tractors will need blade timing. The purpose of the timed blades is so the blades can overlap.

Overlapping blades help prevent uncut grass between the blades. If your blades can touch each other, then yes it’s likely you have a timed deck and the blades will need to be timed. I wrote a post about timing your mower blades here “Replacing timed mower belt”.

Timed Blades

What causes a lawn mower to cut uneven?

There may be several reasons why your mower is cutting unevenly, here are some of the more common reasons:

• Deck wheels are set to different heights (Walk behind mower)
• A bent/worn blade
• Uneven tire pressures (tractor mower)
• Deck needs to be levelled (tractor mower)

Should the front of a push mower be lower than the back?

A lawnmower deck should be level, front to back and side to side. All mowers will have a height adjuster, some will have a single lever, and others will have a height adjuster at each wheel. Level the deck by adjusting the wheel heights.

Level – Adjust all-wheel heights until the deck is level.

What does a high lift mower blade do?

A High lift blade has a trailing edge that lifts sharply upwards. This causes a powerful vacuum effect on the grass blades, lifting them upright before cutting them. The high lift blade is specially designed to collect grass and it does so really well.

An engine will need to be sufficiently powerful to drive a high lift blade, not all mower engines are. Check with your dealer before fitting a high lift blade.

Hey, I’m John, and I’m a Red Seal Qualified Service Technician with over twenty-five years experience.

I’ve worked on all types of mechanical equipment, from cars to grass machinery, and this site is where I share fluff-free hacks, tips, and insider know-how.

And the best part. it’s free!

How to Sharpen a Lawn Mower Blade – Follow These Simple Steps

We can’t count the number of times we’ve been asked by neighbors or colleagues about the best way or how to sharpen a lawn mower blade. Sharpening a lawnmower blade doesn’t require a ton of skill. While years of practice make you better, anyone can learn the basic principles needed to complete the job using any of several tools. We set up this handy lawn mower sharpening guide to work with several different methods. Check out our introduction and then look over the tools you might have on hand to get that lawnmower blade sharpening job done.

Why Sharpening Your Lawn Mower Blades Makes a Difference

I’ve known friends who have never sharpened their lawn mower blade…ever. Apparently, if the mower does something to chew the grass down to 2.5-inches or so, that’s all they require. And it may be natural to think that a blade spinning at just under 200 mph wouldn’t need to be terribly sharp in order to cut grass. You’d be right. However, a sharp lawn mower blade slices through the grass. With a clean cut, your grass stays green and you avoid that unhealthy brown or burnt look that plagues so many lawns—even when they get plenty of water.

Check out the photo below and see if you might start to get the picture:

For professionals and people who want their lawns nice, healthy, and as green as possible, knowing how to sharpen a lawn mower blade makes the difference. This goes double for grasses like Fescue which tend to grow very straight and require frequent cutting.

In the professional landscaping world, some professionals sharpen their zero-turn lawn mower blades every other day. When your business is nice-looking lawns, you need to do everything in your power to ensure you keep them healthy.

How to Sharpen a Lawn Mower Blade With an Angle Grinder

As we mentioned earlier, you can sharpen a lawnmower blade using any number of tools. One of the easiest (and quickest) involves using an angle grinder. Of the people I’m aware of who already know how to sharpen a lawn mower blade, most use an angle grinder. The reason this works is that lawn mower blades don’t need to be razor-sharp. They do, however, need a clean cutting edge—preferably at the proper angle. This clean edge lets the blade slice, instead of chop, through the grass at high speed. It’s the difference between cutting carrots with a knife and a piece of 1/8-inch steel swung wildly through the air

Step 1: Position the Mower on Its Side

The first step may seem obvious but we’ve been around for a while…and we’ve seen some crazy stuff. In case it isn’t already clear, don’t sharpen the blade on the mower. For one, it doesn’t give you enough room to maneuver the grinder. Second—the majority of the work needs to take place on the top side of the blade. Third, it’s dangerous since there’s no good way to keep the blade from spinning around on you.

To remove a lawnmower blade, first, get the mower into a safe position. For a gas mower, remove the spark plug wire to ensure the motor cannot fire. Then turn the mower onto its side (carburetor/air filter side facing upwards) to expose the blade. Turning it this way helps keep the engine from flooding and oil from leaking.

Step 2: Remove the Blade from the Lawn Mower

Use a 1/2-inch impact wrench if you have one. While this may have been an obscure tool for a consumer to have just a few years ago, manufacturers are bringing cordless impact wrenches more and more into the mainstream. So grab a grinder if you have one. If you don’t, use the longest ratchet you have with the appropriate socket. If it’s still not budging, use a piece of 2×4 or similar material and tap the ratchet handle with a hammer via the wood (so you don’t damage the tool). Be careful as the ratchet can easily slip off the center bolt.

Step 3: Secure the Blade in a Vise and Sharpen

Secure the blade in a vise with the sharp portion of the blade positioned accessibly towards you. Using a small angle grinder, sharpen the lawn mower blades using a smooth, steady motion along the length of the sharpened portion of the steel. You want to match the existing angle of the blade, not create your own angle. This ensures the blade continues to maintain its proper lift and functionality.

Remember, the goal of lawnmower blade sharpening…is to sharpen the blade, not recut a new edge from a block of flat steel. Work with the metal! Try to remove the same amount of metal from each side of the blade so you maintain the balance of the blade. See our section below on balancing the lawn mower blade before you finish.

How to Sharpen a Lawn Mower Blade With a Bench Grinder

Knowing how to use a bench grinder to sharpen lawn mower blades helps you in a number of ways. For one, a bench grinder makes it easier to maintain the sharpening angle on the blade. You no longer need to rely on your hands to steady the grinder. Instead, a bench grinder gives you a place to rest the blade against and set up your angle. Let’s assume you already followed the steps above to remove the blade from the mower.

Step 1: Set Your Table Angle to Match the Existing Blade Angle

A bench grinder reverses the process of sharpening. Rather than move the grinder across the blade, you move the blade back and forth across the grinder wheel. Most bench grinders feature a table that tilts. Using this you can really get consistent results using this method. Set the angle of the table before you turn on the grinder and begin sharpening.

Step 2: Start the Bench Grinder and Slide the Blade across the Table

Be sure not to over-sharpen the lawn mower blade when using a bench grinder. You only have so much steel to work with before you have to get a new blade. You also don’t need to do much more than put that edge back on. Use quick passes back and forth when sharpening. This helps keep you from heating up the steel and eliminating the hardening process. This helps you keep that blade edge sharp for longer periods of time.

How to Balance a Lawn Mower Blade

Regardless of how you sharpen a lawn mower blade, you want to finish by balancing the blade. When you remove metal from each side of the blade, you affect the blade’s balance. Just like your car—which needs all four wheels properly balanced—lawnmower blades must also be balanced. If not, it can cause excessive vibration and reduce cutting efficiency.

Step 1: Create a Balance Point

Hammer a 16D or similar nail into a stud in your shed or shop and hang the blade from its center point. In theory, you could simply hold out a nail and do this step by hand if needed. Some blades are harder than others to balance due to the nature of the center hole. The easiest to balance use round holes.

Step 2: Mark the Heavy Side

If it stays balanced, you’re all done. If not, mark the blade on the heavy side with a Sharpie marker. I typically mark the actual sharpened edge so I have something to remove.

Step 3: Continue Sharpening and Re-measure

Next, grind away some more metal off that side. Be sure to maintain the same cutting angle. Just do a little bit and then re-check your blade balance.

Regardless of which grinder method you use, balance the blade each time you sharpen it before mounting it back on the lawn mower.

Other Tools and Methods to Sharpen Lawnmower Blades

Save yourself a lot of headaches and don’t use a file to sharpen lawn mower blades. You don’t need to have that level of accuracy, and it’s just slower and more work than you need for this process. Regardless of what anyone says, you won’t get a nicer-looking lawn or longer blade life from manually sharpening the blade with a file. Use one of the grinding methods above and git ‘er done!

For commercial users who do a lot of lawn mower blade sharpening, several companies make tools that can help speed up the process…potentially. We tried a tool from Noracore called the Easy Mower Blade Sharpener (EMBSX). It uses a die grinder, mirrors, and a camera connected to your smartphone to let you sharpen blades on a zero-turn mower without removing them. While it has some potential, it also had difficulty getting to that center blade on 3-blade ZTs. It’s clearly an innovative tool. In fact, it won a 2019 Pro Tool Innovation Award. In the end, you’ll need to determine whether it might be easier just to jack up the mower and pull the blades.

Other systems include jigs for quickly setting and maintaining angles on even complex mower blades. These help you maintain that proper edge—which can vary between 30 and 45-degrees depending on the blade. If you do a lot of sharpening, find a system that optimizes your time to save you the most money.

Some Considerations

Regardless of how you choose to sharpen a lawn mower blade, be sure you wear proper personal protective equipment (PPE). Protect your eyes, hands, and ears whenever working with grinders. Grinding mower blades takes very little effort. It’s a great entry-level task that almost anyone can tackle.

Let us know what you think in the Комментарии и мнения владельцев below. Do you have a preferred method for sharpening lawn mower blades? Which method works most consistently in your experience? We’d love to hear from you.

Clint DeBoer

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.

Related articles

Husqvarna 300 Series Snow Blowers Recall

The Consumer Product Safety Commission announced on July 6, 2023, that Husqvarna has recalled several models of residential snow blowers. Due to a malfunction that poses safety hazards, this recall applies to the Husqvarna 300 Series Snow Blowers, and more specifically, model numbers ST 324, ST 327, and ST 330. Husqvarna 300 Series Snow Blowers […]

Deal Alert: Makita 36V LXT Mower Kit

As the dog days of summer roll in, Home Depot has got a killer deal for willing yard warriors. If you’re looking to beat hot emissions and rising gas prices, there’s the Makita 36V LXT Mower Kit. And while there are plenty of good things to say about it, perhaps the best news is that […]

Deal Alert: EGO String Trimmer and Blower Combo

As the old saying goes, membership has its perks. That’s certainly true when it comes to this deal. Join the Ace Rewards program and get 90 off the EGO Power ST1503LB 15 in. 56 V String Trimmer and Blower Combo Kit. Just to break this down, you’re getting a 56V string trimmer and a 530 […]

Amazon Prime Day

When is Amazon Prime Day? July 11th – 12th, 2023! Word is that this year’s Amazon Prime Day is going to be July 11 – 12. What does that mean? Well, crazy deals, of course. And while much of the hype surrounds discounts on electronics like Amazon Kindle deals. Amazon Fire Tablets. earbuds […]

As an Amazon Associate, we may earn income when you click on an Amazon link. Thanks for helping us do what we love.

How to Sharpen Lawn Mower Blades

Certainly one of the most repetitive lawn mower maintenance tasks there is no matter what type of lawn mower you have. In this article, we will look at 3 different options you have when it comes to grinding your mower blades and lawn mower blade sharpeners to consider.

Lawn Mower Blade Sharpeners

1st we will go over the ‘traditional’ angle grinder method. This is very effective and requires the smallest investment in equipment. It is going to be the most time consuming and leave the most room for user error.

Next, we will take a look at the professional blade grinder made by RBG. RBG has several models available but the RBG 712 Blade Grinder is the most popular by a long shot and for good reason. It is incredibly efficient and leaves little to no room for user error.

Finally, we will check out the EMBSX by Noracore which is the world’s first blade sharpener that does not, I repeat, does not require the removal of the blades from your lawn mower!

And if you thinking the EMBSX will never last, you are correct, they are already out of business and the EMBSX is no longer available! We still wanted to leave it in this article for historical sake!

How to Use an Angle Grinder to Sharpen Lawn Mower Blades

Using an angle grinder and vice grip is probably the most common way people sharpen their lawn mower blades. This goes for homeowners and small businesses alike.

Many homeowners, and even some businesses, will actually take their blades into the local mower shop to have their mower blades sharpened. Although this is an option, we feel the cost (over time) and time involved in this makes it less than ideal, to say the least.

Here is a great video on blade sharpening with an angle grinder:

If you watched the video or were already familiar with this method of sharpening mower blades, it simply involves removing the blades from your mower, inserting them into a vice grip 1 at a time, and grinding the cutting edge with an angle grinder. After grinding one side of the blade, you need to rotate the blade 180 degrees in the vice to grind the other side of the blade.

Although this is a relatively quick process, the other options are much quicker and more accurate. Lawn mower blades come from the factory with a specific angle on the angled edge. This angle should be kept as you grind your blades over time.

The most common lawn mower blade angle is 30-35 degrees. When sharpening your mower blades it is important to keep this 30-35 degree angle over time.

Since the person operating the angle grinder is solely using their motor skills to keep that angle, it leaves the door wide open to alter the degree of the angle. Not that this is the end of the world, the blade will still cut the grass, but there will be some quality/performance loss.

Who Typically Grinds Blades With An Angle Grinder?

This is going to probably be the ‘best’ way for a homeowner to efficiently and cost-efficiently maintain their mower blades. We say that because they more than likely have a single lawn mower which has one or two, possibly three blades, to sharpen each time sharpening is due. This only this volume of blades to sharpen, this is a perfectly acceptable method.

It also very well may be the best option for smaller lawn care, lawn mowing, or landscaping companies since it does not take that much longer than the other methods, and the cost savings it pretty significant in comparison.

We honestly feel looking at the other methods is warranted when you have 5 mowers in your fleet. The time-savings could be cheaper than the cost of the blade grinders in the long run and provide better results.

Cost Of Grinding Mower Blades With An Angle Grinder

You may have everything you need to do this already effectively making it ‘free’ to start sharpening your blades in this manner.

Angle grinders run from 15 to 100 and a vice grip is going to be 30 and up.

You will probably want to consider grabbing some replacement grinding discs. 4.5 disc diameter is a great size for grinding blades with an angle grinder. Also, consider purchasing a ‘flap disk’ instead of the metal grinding wheel to keep your blades cooler during the sharpening process.

Blade Grinding With The RBG 712

The quality of the build and simple design of the RBG 712 attracts many eyeballs and makes it the choice of many lawn care professionals and serious DIY homeowners.

There is little room for error when using the RBG 712 grinder.

The guides are set to 30 degrees which is the most common angle of a cutting edge on a lawn mower blade. The blades do still need to be removed from your machine, but instead of grinding by hand with the angle grinder, the machine makes quick work of putting the 30-degree edge back on your blades.

Often, in as little as 2 passes your blades will be razor-sharp once again. When using an angle grinder it is not uncommon to make 10-20 passes back and forth across the cutting edge in comparison.

Who Typically Grinds Blades With A Professional Grinder Like The RBG 712?

The RBG 712 is ideal for DIY homeowners who are lawn care fanatics with some extra money to throw around and professional companies alike.

If you do have multiple mowers in your fleet, this can save a lot of time when compared to grinding several blades one after the other with an angle grinder.

Cost Of Grinding Mower Blades With A RBG 712 Grinder

iGoPro Lawn Supply has the RBG 712 grinder for sale. We do recommend to also purchase the ‘RBG 712 Grinder Grit Collect’ as this will greatly reduce the amount of dust entering the air.

The grit collector for the RBG 712 will last forever. The grinding disc last for hundreds of sharpenings. We do also carry replacement grinding wheels and they are specific to this unit. The grinding disc on the RBG 712 keeps the blades cooler than a typical metal grinding wheel.

The EMBSX. The Easy Mower Blade Sharpener

Update: The EMBSX is no longer available as the company has ceased production!

No doubt, the EMBSX is the coolest blade sharpener on the market today !

You do not even have to remove the blades from your lawn mower!

Developed by engineers, the EMBSX is properly nicknamed The Easy Mower Blade Sharpener, hence EMBSX.

We love the well thought out design which also includes all tools you may need to make adjustments to the height/cutting angle. And, since you will not be able to directly see your blades while grinding, it has a mirror and Wi-Fi camera with a free app to get you the visibility you need.

Honestly, after using the tool a couple of times, you very well no longer need the assistance of the mirror or camera.

Final Thoughts On Mower Blade Sharpening

The are several ways to skin this cat, or sharpen those lawn mower blades in this case!

The key takeaways on how to sharpen lawn mower blades are to determine if you’d like to spend a little more for speed and accuracy or save some money by doing it the ‘old fashioned way’ with an angle grinder and vice grip.

Honestly, the ‘old fashioned way’ was literally with a hand file! Any of the methods on how to sharpen lawn mower blades covered in this article are a better option than that!

If you are interested in the EMBSX or RBG 712 blade grinder, iGoPro Lawn Supply is an authorized dealer of each product.

It’s super important to keep your mower blades sharp, so please, no matter how you do it, please do it right and do it often.

Also, do it safely! Always be extra cautious when removing your mower blades, grinding your mower blades, and installing your mower blades. Be sure they are properly and securely reinstalled on your mower. The last thing you want is a freshly sharpened mower blade flying into the neighbor’s living room!

Ryan Sciamanna

Ryan is the owner and founder of Lawn Crack, LLC the parent company of iGoPro Lawn Supply. He has worked in almost every capacity within the lawn and landscape industry for small local companies, nationwide companies, and of course, owning his own lawn landscape business which he sold in 2018 before starting selling lawn and garden products online. Learn more about Ryan by subscribing to the LawnCrack YouTube Channel.

How to Sharpen Lawn Mower Blades

Is your lawn looking ragged and bland instead of healthy and lush? It may have lost its luster as a result of cutting your grass with dull mower blades. You can help bring your lawn back to life by learning how to sharpen your lawn mower blades. The purpose of this guide is to provide you with step-by-step instructions on how to sharpen a mower blade and let you in on some helpful tips, but before we do, let’s look at why sharpening your mower blades is so important.

“Sharp lawn mower blades create a cleaner cut, which improves the health of your lawn. Learning how to sharpen a mower blade is an integral part of maintaining a healthy lawn.”

Why Are Sharp Mower Blades Important?

Cutting your grass with a dull mower blade is sort of like having split ends in your hair. It inhibits healthy and vibrant growth. When you cut your grass with dull mower blades, it tears the blades of grass rather than cutting them. Not only does this contributes to the ragged appearance of your lawn, but it leaves your grass susceptible to diseases. With sharp mower blades, you get a clean cut, which allows your lawn to stay healthy and retain its vibrant luster.

Step-by-S tep Guide to On How to Sharpen Lawn Mower Blades

Sharpening a lawn mower blade is not as difficult as you might think. Once you learn the best way to sharpen mower blades, you won’t hesitate to repeat the process two to three times per season. You will soon find that your mower operates better and your lawn remains healthier. There are four main steps involved in the process.

Step One: Preparing to Sharpen the Blade

Preparing to sharpen your lawn mower blade is an essential part of the process. If not done correctly, there is a potential for disastrous results. Follow these steps carefully to produce the best results:

Assemble the Following Tools and Equipment:

Safety goggles or safety glasses.

2×4 wood block 16” to 20” long.

4×4 wood block and boards of various thicknesses 12” to 18” long (optional).

Paint stick, permanent marker or spray paint.

Breaking bar with a socket.

Wire brush and/or steel wool.

Using safety equipment is an essential element. Wear safety goggles or safety glasses and gloves before and during all the steps.

Disconnect All Sources of Power.

Be sure to disconnect all potential power sources before you begin work on your mower. If your mower is electric powered, be certain that it is unplugged. If your mower is gasoline powered, your best bet is to disconnect the cable from the spark plug. Failure to follow these steps creates the potential hazard that the machine could suddenly start or turn over while the blades are exposed.

Turn the Mower on Its Side.

To get at the mower blade, you need to turn the mower on its side. Either side is fine if your mower is electric powered, but a gas mower should be turned so that the carburetor is facing up. By turning the carburetor up, you prevent fuel from flooding the carburetor, which causes issues when you get ready to start your mower. Placing a block under the motor or engine housing helps to stabilize the mower while you work, you may need more boards of various thicknesses for greater stability.

Step Two: Removing the Blade

Removing the blade requires a bit of torque and a lot of caution to prevent injury. To safely remove the blade, follow these steps:

Mark the bottom side of the blade.

A major mistake many people make when removing lawn mower blades to sharpen them is installing them upside down when they put them back on. A simple way to avoid this issue is by marking the bottom side of the blade with a paint stick, permanent marker or a quick dab of spray paint. Find a place on the blade that is free of debris, so your mark remains after you clean the blade.

Block the blade for removal.

When you get ready to loosen the nut, which secures the blade to the driveshaft, you need to prevent the blade from turning. By wedging a 2×4 under the blade and over the cutter deck, you will pinch the blade so that it won’t turn. Keep in mind that you need to provide resistance from turning counter-clockwise. Place the wedge from the top, right side of the mower deck.

Remove the blade.

Removing the blade takes a significant amount of torque. Make sure that you have a breaking bar that provides plenty of leverage and equip it with the proper socket to fit the drive nut. Place the socket over the nut with the breaking bar a little above the nine o’clock position. Apply downward pressure on the breaking bar to break the nut free. You might have to apply penetrating oil to the area around the drive nut and washers if the nut is particularly stubborn.

Once the nut is loose, unscrew it, remove the blade and the washers. Pay attention to the number of washers and sleeves, as well as their placement, so that you can replace them in the correct order when you reinstall the blade.

Step Three: Sharpening the Blade

With the blade removed from the mower, you can sharpen it in a more comfortable position and do a better job of honing the edge consistently. The following steps will help ensure greater success in sharpening your mower blades:

Secure the blade.

The reason for removing the blade from the machine is so that you can get at it better to sharpen it. Once it is off of the machine, it is best to secure it in a vice. Place the end of the blade with one of the cutting edges in the vice with the cutting edge facing upward. Tighten the vice until the blade is secure.

Clean off the blade.

It is common for grass and rust to cake your lawnmower blade. Though you won’t need to clean off the entire blade (although the edge lasts longer if you do), you want to make sure that you clear all of the debris near the cutting edge so that you have better access to the edge for sharpening. You can use steel wool or a wire brush to clear away this debris. Especially stubborn buildup might require a cold chisel to remove it.

Sharpen the blade.

Most people sharpen lawn mower blades with a flat file, but some also use a hand grinder. Your technique may vary a bit with each tool, but there are several standard guidelines to follow, including:

Be sure to maintain the proper angle, typically 45 degrees.

Make even strokes from the inside of the cutting edge toward the outside, moving away from you.

Do not draw backward, regardless of whether you are using a file or a hand grinder.

Once you have finished one edge, flip the blade over and sharpen the other edge. Use the same technique and as close to the same number of strokes as possible, so the edges are uniform.

Bench Grinder Alternative

A bench grinder is particularly useful if the blade is severely nicked, but it also makes for pretty short work when sharpening as well. If you have a bench grinder, you can remove the blade from the vice after cleaning it and sharpen the blade on your bench grinder. Be sure to follow the proper angle of the blade.

Step Four: Reinstalling the Blade

Once your blade is sharp, you need to reinstall it on your mower. To be sure that it is properly installed, follow these steps:

Properly position the blade.

If you marked the bottom of the blade with a paint stick, permanent marker or spray paint, properly positioning the blade is much simpler. Be sure to have all the washers and sleeves on hand and place them in the right order as you thread the nut through the hole on the blade and into the drive shaft. Finger-tighten the nut as far as you can.

Tighten the nut.

Before you can tighten the nut, you need to place your 2×4 wedge on the left side of the mower deck so that you have resistance against clockwise turning of the blade. Secure the socket with the breaking bar above the three o’clock position and apply downward pressure. You need to repeat this several times until you cannot turn the nut anymore.

Prepare to mow.

With the blade secured in place, you can remove your wedge, tip the mower back up onto its wheels and prepare to mow. If your mower is electric powered, you plug it in, turn it on and get started. If your mower is gasoline powered, you need to remember to reconnect the spark plug cable before attempting to start it.

How to Sharpen Lawn Mower Blades without Removing Them

Though you have much better access and it is more comfortable to remove the blade from your lawn mower to sharpen it, you can sharpen it without removing it from the machine. The following steps show you how to sharpen lawn mower blades without removing them from the mower. By not removing the blades, you can complete the task using only two steps.

Step One: Preparing to Sharpen the Blade

Preparing to sharpen your lawn mower blade without removing the blade is similar to preparing to when you removed the blade. If not done correctly, there is a potential for disastrous results. Follow these steps carefully to produce the best results:

Assemble the Following Tools and Equipment:

Safety goggles or safety glasses.

2×4 block of wood 16” to 20” in length.

Additional 4×4 wood block 12” to 18”.

Wire brush and/or steel wool.

Using safety equipment is an essential element. Wear safety goggles or safety glasses and gloves before and during all the steps.

Disconnect All Power Sources.

Just like when you removed the blade, it is essential to make sure that all potential power sources are disconnected to prevent accidental starting or turning of the blade while you work. Unplug the power cord or disconnect the spark plug cable from the spark plug.

Turn the Mower on Its Side.

Turn the mower on its side, just like above with the carburetor is facing up on a gas mower. Placing a block under the motor or engine housing helps to stabilize the mower while you work, which is far more critical when you sharpen without removing the blade.

Step Two: Sharpening the Blade

Even if you do not remove the blade from the mower, you follow the same steps to sharpen it. However, executing these steps is a bit different.

Secure the blade.

Though you won’t need backward resistance to remove the blade, you need to secure it so that it doesn’t move while you are trying to sharpen it. Wedge a 2×4 under the blade and over the cutting deck to prevent the blade from turning while you work.

Clean off the blade.

You want to knock off any caked grass, rust or other debris from the blade so that you have unobstructed access to the cutting edge.

Sharpen the blade.

Though access is a bit more difficult, use the same technique for sharpening the blade with a file or hand grinder that you would use if you removed the blade. Here is a brief reminder of those guidelines:

Maintain the proper angle.

Even strokes, moving away from the center.

Once you have finished one edge, turn the blade over and sharpen the other edge.

Helpful Tips

Following the above steps whether you choose to remove the blades to sharpen them or sharpen them on the mower. However, there are a few tips to keep in mind that help make the process easier. Here are some of the best tips:

Knowing When Blades Are Dull. Check the blades of grass on your line and look for signs of splitting and tearing at the tips.

Sharpen When the Gas Tank Is Empty. You can prevent fuel loss by emptying your mower’s tank before sharpening or sharpening blades when it is empty.

Make Sure the Blade Is Properly Balanced. Be sure that the blades are properly balanced. You will hear funny noises under the mower deck if it is not. Improper balance comes from the blade becoming bent or the driveshaft hole being wallowed out.

Dealing with Nicked Blades. A nicked blade does not always mean that the blade is ruined. A nicked blade can be ground out, but you should use a bench grinder for best results.

Know When It Is Time to Replace Your Blades. A wallowed out driveshaft hole, a bent or out of balance blade or a blade with nicks beyond repair are all good reasons to replace your blades with new ones.

Summary

If your lawn is looking a bit ragged, the answer to restoring it to better health could be a simple one. Sharp lawn mower blades create a cleaner cut, which improves the health of your lawn. Learning how to sharpen a mower blade is an integral part of maintaining a healthy lawn. Follow these step-by-step instructions for the best results when sharpening mower blades. So get into it and start sharpening those blades!

How to Sharpen Lawn Mower Blades

When you mow your lawn with the dull blade of your lawnmower, your grass can turn brown due to the ragged cuts. For this reason, it is important to have sharp lawnmower blades. It can keep the grass healthy and green and the mow will also last longer.

All you have to do is to sharpen the blade to have clean cuts. In doing so, your lawn mowing time will be reduced and the grass can recover quickly. Here we shall explain to you how to sharpen the lawnmower blade safely.

Requirements –

The tools required for sharpening lawn mower blades are socket wrench or ratchet set, vise, bastard-cut mill file, and rags. The materials that you require will be work gloves and WD-40 lubricant.

When To Sharpen Your Mower Blade?

When you cut the grass, the nutrients will return to the lawn so that there will be strong and green-looking grass. For this, it is important to provide clean cuts. You can offer a clean cut with a sharp mower. However, with regular use, the lawnmower blade can become blunt and dull. It is important that you inspect the blades from time to time.

• When there are worn-out blades, you will have to remove them and hone the edges.
• It is advisable to sharpen the mower blade at least twice a season.
• Some people often tend to sharpen the blades after 25 hours of use.
• You will also have to sharpen them when the blades hit rocks which can cause dents.
• At times you will find it difficult while mowing, where the lawn will give you hints that the blades are dull.
• You have to look out for different signs like uneven grass height, dents or nicks, torn-looking blades, or frayed grass edges.

Removing and Cleaning Blade

To sharpen the blade, you will have to safely remove the blade from the lawnmower. It is always advisable that you disconnect the power source or battery. Always disconnect the spark plug wires. It helps to protect from any kind of shocks due to power. You can do it in the following way:

• For better safety, you can wear protective eye gear and gloves.
• Firstly, always drain the gas tank which will help to prevent fuel spills. You need to turn the mower on its side carefully. However, make sure that the carburetor and air filter are on the upward-facing side.
• Use a permanent marker or a grease pencil to mark the bottom of the blade. In doing so, you will be able to install it right side up after sharpening the blade.
• Now you will have to look out for the nuts. By using a wrench or a socket, you can easily loosen the nuts to release the mower blade. Apply more leverage if the grip is very tight. You need to clamp the blade and brace it with a piece of scrap wood.
• If in any case the threaded shaft and nuts are stuck together, you will have to apply penetrating oil. Always allow it to sit in for a couple of hours.
• Before sharpening, you will always have to clean the blade with a microfiber cloth or a dry rag. At times you may find the blade to be covered in grass clippings where you will have to use penetrating oil. Allow it to sit for some time and then scrub the debris with a stiff brush.

How To Sharpen Lawn Mower Blade?

To prepare for cleaning, you will have to gather the tools. You will first have to confirm if the blade is damaged or dull. Keep in mind the opposite sides of the blade have a cutting edge of up to 4 inches. To examine the blade, you will have to clamp the mower blade onto a worktable. Keep the cutting edge facing upwards. Look carefully for the signs if it requires sharpening or replacement. A replacement has to be done if the blade has cracks or if it is severely bent. If the blade is dull or chipped, you will have to sharpen it.

The lawnmower blade sharpening can be done in multiple ways. To sharpen it with the hand you will require abrasives or metal files. If you are looking to sharpen it with a machine, you will require a bench grinder, angle grinder, or blade sharpener.

While sharpening you will have to do it safely so that it will not cut your finger. If it is a razor-sharp blade, the likelihood of becoming dull is even more. It is advisable to go for replacement rather than have constant sharpening.

Sharpening by Hand

Always begin by wearing protective gloves and eye gear. You will have to protect yourself from metal shavings and sparks.

• Use a grindstone or a file of 10 inches to sharpen the blade’s edge. You need to keep the file approximately about 45 degrees.
• Begin by sharpening from the top side.
• You will have to push the file in one direction without sawing back and forth.
• While filling, you will be able to feel the file teeth. When there is no such feeling, you will have to apply a little pressure.
• Try to reach rough spots and follow the blade edge’s angle. Do note that most blades require sharpening in less than 50 file strokes.
• After finishing one edge, you will have to release it from the vise.
• Repeat the process by turning it over to the other side.

Sharpening with Blade Sharpener

Here also you will have to put on gloves as well as hearing protection.

• You will have to begin by clamping the blade into a vise.
• Take a standard drill and insert the blade sharpener into it. The blade sharpener comes with a grinding stone that has a beveled edge. It also features a shank of 0.25-inch and a guide piece.
• Begin by pulling the drill trigger to start it.
• You can now place the grinder on the mower blade. To have the right sharpening angle, you must keep the flat guide against the blade rear. Also, the cutting edge must slot into the bevel.
• By applying medium pressure, you will have to move the stone back and forth. Check the blade after every five strokes. It has to be free from any rough spots or nicks and must be very sharp.
• Complete the edge and then turn the blade over. Begin the process and sharpen the other edge.

When you happen to use a power sharpener, never overheat the blade’s edge. If it is ho,t you can dunk it in a bucket of water.

Sharpening with Angle Grinder

To begin with, you will always have to wear safety gear like ear and eye protection and work gloves.

• Clamp the blade by using a vise. For the angle grinder, you can use a flap disc.
• It is advisable to align the mower blade cutting edge with the grinder’s blade.
• You need to move the grinder slowly against the edge of the blade.
• Try to do it on the existing edge and make sure there are no rough spots.
• After completing one edge, you can repeat it by turning it over.

If you feel that the sharpening is complete, you can always check it. Get a piece of paper or a blade of grass and it must cut easily.

Check Blade Balance

Before you install the blade, it is important to confirm the blade balance. An unbalanced blade can lead to vibrations that can damage its components. A well-balanced blade will have smooth running. Any imbalance can even damage your mower and you will have to look for a replacement. There are even ways to check the blade balance by using a blade balancer. You can confirm it in the following way:

• You can begin by supporting the blade like a scale and using a screwdriver. Now insert the tip of the screwdriver in the blade’s hole. You will find that the blade will balance or drop on the handle.
• Holding the blade horizontally, you must let it go. In this process, keep in mind that it should remain level.
• The primary sign of an unbalanced blade is that the blade drops at one side.
• It can even happen that the depth side is heavier. You will have to remove some metal by taking off a few strokes.

Reinstall the Blade

Reinstalling the blade is a key factor in determining the overall performance. If it is under tightened, then it will make the mower hard to start. During this process, you can easily clean the bowl around the blade. Make sure that you like the area clean which is under the mower. Remove any grass clippings or mud by using a putty knife or scraper.

• Begin by inserting the blade onto the bolt. Do note that the marked side must be upward.
• By using a socket wrench, you can tighten the nut. It has to be secure and must be extremely tight so that the mower can start smoothly.
• You can now connect the spark plug wire as well as the power source.
• In the next step, you must refill the gas tank.
• To prevent any fumes, you will have to roll the mower outside the shed or garage.
• Finally, you can see if the mower starts smoothly.

How to Maintain Your Mower Blade?

Blade maintenance is an important thing for or perfect lawn. You will have to sharpen your blade at least twice during the mowing season. It can provide a healthy lawn and your mower will be in good shape. It does mean that you will have to keep good attention to the blades. You will have to sharpen the mower blade every time you have used it for up to 25 hours. For this, you can calculate the time you have mowed in a season. By keeping sharp blades, you don’t have to worry about getting a new one. In doing so, your blade can last longer.

Conclusion

We have discussed how often should you sharpen your blades. It is very important to sharpen the mower blade. Sharp blades offer clean mowing and can save you money. It can last very long when there is proper maintenance. You will have to look for any signs which can actually compromise the performance of the mower. However, you must maintain safety while sharpening the mower blade and do it carefully.

One Response

Hi, I really liked the articles on sharpening lawn mower blades. But I have come up with a question. I have a lean mower with two blades. So when I put them back on how do they need to go back on? I mean like should they be placed like this – – or || or — l. Not sure how to explain it. Do the blades both face like on a clock 9 to 3 or do I place on blade at 9to3 the other at 12to6? I hope you can understand what I’m trying to ask. Thanks Mark