How to sharpen lawn mower blades THE CORRECT WAY ( Angle grinders will destroy your mower blades) 

A properly used angle grinder will not destroy your blade.

I'm now 47 years old in 2024 and this exactly how my father used to do it and he was wonderful enough to teach me how. It's been 16 years since he passed but I still remember every lesson

I, and apparently everyone here, uses an angle grinder. In over 40 years of sharpening my own, as well as friends and family, never have I had one issue. The balancing part is really simple . . . place a round-tang screwdriver horizontally in the bench vise and slip the blade onto it. It will balance itself perfectly level if it is balanced at all; a sagging or drooping blade angle will tell you which end to grind off a little more. This has worked for me for like ever.

I’ve used an angle grinder for years on my mower blades. We cut 75 lawns a week for 25 years now and never had a problem

To all of us who use flap wheels on our grinders and know how to use the tool, sharpen away and use the cone balancer to balance after we are done. Work smarter not harder. 🙂

Installed these on a riding mower ru-vid.comUgkxetgfkJxfdT_B2vGYP-uNTLaBbim9OKTD . They were sharp out of the box, although I've never liked blade edges that were coated...not quite as sharp as I personally want. Using my belt sander, I removed the coating from the cutting edges and refined the edge enough to shave with them. So far, after three runs, these blades are holding up as expected. Even after hitting a few fallen 1/2 inch or so branches, the edges are still sharp as heck. No edge dings, no warping, etc. As far as installing them, the cutouts were of the proper size and shape to fit my aging Craftsman mower. Very satisfied.

This larger die grinder ru-vid.comUgkxmwiwyX3ADeryrwvcsiwLeKxme6QNQmGL runs very smoothly in use. There's virtually no vibration. Paddle switch with the safety trigger is a bit cumbersome to use, but is much safer. Grinder cannot turn on if set down on the bench.Note that this die grinder, like most others, runs at 25,000 rpm. Always use a face shield and hearing protection. If your grinding stone has any sign of chips or cracks, throw it away. At 25,000 rpm, the stone sees very high G-loads and could come apart explosively if the stone is damaged. Always run the grinder for a short time before using it to check the stone.This tool is heavier than some but very well made.Recommended.

No disrespect. The file works well for people in the city that cut postage stamp size lots with manicured type grass. In the real world of rural living where it takes hours to cut grass in all kinds of scenarios the angle grinder is the only and best way to do that. 51 years of doing it says so.

You can use your file. I'll use my angle grinder with a flap wheel disc. Works great!

An angle grinder with an 80 grit flap wheel works well for me. I have been hand sharpening, file or bench grinder, for about 50 years about 2 years ago I started with the flap wheel, fast enough that you don't build the heat to pull the temper, slow enough to not make an error too quickly.

I always love these videos because they use brand new or barely used blades to show how to sharpen them and always speak out against using a grinder. I would love to see anyone sharpen the blades I pulled off of my riding tractor this week with a file. It would take a week. I did appreciate the nail trick for balance rather than buying that specialty tool. Thanks for the video but I still had to use a grinder on mine just to get the chunks out of it and then I did do a final run with the file once I had it really close.

Growing up I would watch as my father deftly used a mill file as he started from the back edge of the bare metal to the front cutting edge. Neatly taking about a millimeter of steel with each pass, he quickly brought down the surface to a razor sharp finish on the last pass…never going over the cutting edge more than one time. It was almost as if you could calculate how many strokes it would take him to reach the final sharp finish. I am 60 now and endeavor to match that technique each time I sharpen my blade…as I think of my Dad.

Takes experience and skill. No guessing game once you become one with the tool! Been in the business for 20+ years and angle grinder is by far the best way to sharpen blades

I prefer waiting until after the first mowing in the spring to sharpen it that way I can find all the sticks, rocks, bear cans, and whatever else blew in over winter with the dull blade and then I can have a nice sharp one all summer. As for using a grinder to sharpen it, the key is to watch what your last pass did and make tiny adjustments not to try to see the actual point of contact. He was right about not leaving burs though, if you leave them on they may try to roll under making the blade dull a lot faster than usual

Lightweight is good and what did I use it for it’s a lawnmower ru-vid.comUgkxTPN04aT-Qdjr_KS3ql7ng8wnU3wwsCqk also recommend Yes it is lightweight so hence not as robust as our old one. But if you take care it does the job really well.

I always take the file and make a very narrow flat edge, 1/16" or less, along the cutting edge. It's gives you two cutting corners and is more resistant to denting than a sharp edge. Over my over 50yrs of mowing (I'm 78) I've found that this works very well.

I have sharpened my blades for years with a carbide disk on a 7" angle grinder. Works great and is fast. Make sure the blades are balanced and edge is reasonably straight and you're good to go.

Been sharpening mower blades with a 4/1/2” angle grinder successfully for almost 20 years. I use the 80 grit flap wheels. Works well for our business.

Great video. I agree 100% and I have used a file for sharpening for over 30 years. Two points to consider. WhenI file the blade I watch for a burr to firm on the back of the edge. This lets me know when the new edge and back of the blade are tangent. That’s when I file as you have demonstrated, with the file straight up, or I use a fine hand stone to remove the burr. The second point is that most blades are mass produced and induction hardened, so the hard surface is about 45-50 Rockwell. Using any kind of grinder or belt, WITHOUT coolant, will heat the blade over 800 degrees at the point if contact, and is hot enough to anneal the edge (draw away the hardness) thereby reducing the ability to hold a sharp edge. 👍great job in demonstrating the proper method. This also works on hand shears, pruning shears etc.. Don’t grind unless you have flood coolant as you are grinding.

I'm all with you from the good old-school mechanical perspective. I however mow my healthy green though bumpy field each week and accept the consumption of one set of blades per season. With that I am perfectly ok with using my angle grinder for a periodic sharpening. My 9 year old Simplicity tractor never suffered any motor or bearing issues

Lot of people on here that post videos think they have all the answers. Been using an angle grinder for years and never had any issues. I will continue to do so.

I’ve seen about 6 videos of sharpening blades and you are the first one that talks about balancing! I’m like that’s a little important…. Thanks for sharing

I agree that a file works well on a blade that is barely dull, but in reality, most people let blades get very dull. A flap disc works very very well in this situation. A file would take awhile and wear you out. For those who don't know how to balance a blade, simply grind/sand/file a little more off the heavy side until it's balanced.

I’ve been using my vertical belt grinder with a 36 grit for years. Makes quick work of the six blades I have to sharpen every year. Does a great job.

If I had to use a file to sharpen mower blades I would spend hours to sharpen a blade for my customers for a 2 min job. Using an angle grinder is how most pros do it if they don't have a proper blade sharpener. I can literally sharpen a badly dented beat up blade in a couple of minutes. It will not destroy your blade if you pay attention. And it's not the end of the world if you mess up a mower blade to be honest if you learn in the process it's not like they are horrendously expensive and then in the future the money you will save by doing it yourself will more than pay for that blade you may have messed up.

I've been sharpening my blades for over 40 years and never had to guess the angle. I have 10 year old blades still in service. Always grind and balance.

Perfect, a nice basic to the point video. I like the tip at the end for balancing. Thumbs up!

I too watched my Dad sharpen his table saw blades and hand saws with a hand file for so many years, he was a carpenter who would rather use mostly hand tools except for his circular saw blades for ripping plywood. Watched him sharpen my lawnmower blade and my chisels on a wet stone and have been doing it this way ever since. Thanks Dad.

I have used angle grinder for years. The secret is to wear eye protection and watch where you are cutting. I have to sharpen fairly often as we have moles round here and the little sods bring up stones that are had to spot in the grass.

I owned a landscape and maintenance company for 20 years with 185 accounts scattered in 5 counties. We changed blades every morning and never had issues using an angle grinder. I'd hate to know I had to sharpen 36 blades at a time with a file.

I love watching smart people give advice.. thank you!

Thanks man. Took the deck off to pressure wash the bottom And spray paint it to prevent rushing and thought I’d sharpen the blades while I was at it 👍🏼

20 years of driving hay mowers and sharpening 20 blades every couple days with a grinder without even removing them tells me that a grinder is the right way for some of us. Also, the tip of the blade does the majority of the cutting so that's the most important part to get right.

Angle grinder with about an 80 grit flap disc. Run a sharpie marker over the edge so you can see what angle you're sharpening at. Hold that angle and keep the angle grinder moving so you don't overheat the edge. Balance when done by removing a little bit more metal from the heavy side of blade - some people don't balance and feel like it doesn't affect their spindle life. They may be right, but the smoother my machines run the less fatigue I feel at the end of the day. I still have plenty of sharpenable edge left by the time that the kicked up lift portion at be back of the blade has worn paper thin and is about to start shedding pieces. Can you do a whole lot of damage with any high-speed tool? Yes, but, mower blades are cheap, used practice blades to develop your technique are even cheaper, and time is expensive. I'm also going to be keeping my cordless bit driver, my belt sander, my router, my chainsaw and a number of other tools that can do damage if you use them wrong way.

September 2022 in Virginia Beach. Great video! Yours is the first one I've found that showed the proper way to sharpen the blade with a file! I have an angle grinder, flap wheel, all of that. I considered using that but I don't have the steadiest hand. Thanks for the video, you just got a new subscriber! (and to the guys who prefer grinding the blade, to each his own!) I'm not at that level yet!

Perfect! to the point, nice speed as the video progresses, voice, appearance, etc. Good and very helpful video, especially the warning of the consequences and importance of balancing the blade afterwards. Thank you!

I’ve used an angle grinder to sharpen blades for years and it works very well. If you’re new to this process and still have the guard on your grinder it helps a lot to keep the angle the same across the length of the blade by holding the guard against the blade to steady yourself. And I haven’t technically balanced a mower blade in thirty five years and it’s never wrecked any bearings, belts or engines and my lawn looks as good as the next guy’s so….

The file absolutely adds more precision, and allows you to carefully remove just enough to sharpen and adjust to balance, this can also be done with a diamond lap (the little fiskar files in the garden center). With that said, we are sharpening a coarse bevel (no need for precision) and any experienced individual with an angle or even a bench grinder can achieve the same end in far less time. Most beginners that just purchased a cheapo HF AG can easily butcher their blades, if they even manage to remove them.

Thanks for the video, I was sharpening blades for a Toro 455d, 126" cut. Heavy metal, was using angle grinder and agree that its not the way to go. So i took them off and used a bench grinder stone that had wire brush as well. These blades had notches, took work but it worked. Biggest deal of all was balancing them, so glad i found your vid because for some reason vibration full throtle made me think a bearing was going or spindle, but no, just bad blade maintenance. Now i run it full throttle no vibration, so thanka for that. Having off balence blades after some time will wear ktger parts and everything on big heavy duty mowérs are expensive.

Just discoverd flap wheels a couple of years ago after decades of angle grinder. Game changer! So easy and does a great job fast.

Long time ago, Harbor Freight offered a large (10") bench grinder, which i picked up and use for sharpening blades. Unlike all the other bench grinders I've seen, it turns at half the speed of the others... 1800rpm. The reason you want to file VA bench grind is the speed of the grinder taking the temper out of the blade steel. Sure am glad I've held onto it for all these years~

Whatever keep hand filing if that's what you think is best. I know from experience an angle grinder works just fine and does a great job as long as you don't use regular grinding discs. I use 80 grit flap disc and a couple passes is all it takes to restore the edge and it doesn't build up any heat and the angle stays exactly the same.

Good stuff, no fluff and straight to the point.

Yes I agree with the File method. After cutting a dozen or more lawns a week times 10 years- one gets Good at treating the mower properly. The lawnmower is for cutting lawns- not large weeds, vines and other. It's not a stump grinder! Just grass

We subscribed because your presentation was clearly organized, concise and based on experience. (And you held our attention, without background intro music.)

I use an angle grinder. I apply light pressure against the blade. It's rather easy to place the grinder at the existing blade angle. Pay attention to your sharpening progress as you go, don't overdo it. The blade has always been fine for me, no damage.

Nice touch up on a blade in great shape to begin with.

Really good video been working with riding lawn mowers for a while definitely didn't know some of the tips especially the finishing nail for balancing the blade way easier thanks man keep up the good work

I used to sharpen my mower blades with a file BITD but now I do it with an angle grinder and a mild flap disc. Just don’t use an overly aggressive disc and watch the angle, perfect balancing is much easier to get with a disc too IMO. Right tool for the job!

I built a stand the I mount my blades to that makes a 30 deg angle cut on mine every time. Not much metal is taken off at all. Built out of a 4x4 and some mounting hardware. I learned it from Clean & Green Lawn care. .

Good video, and to the point. The file does a good job and the nail to hang the blade on is super accurate. Beats a 100.oo balancer. Thanks

Well done mate. Great video. Not too long and to the point. Educational and decisive. Off to sharpen my blades now. Thank you

Using a balance cone rather than a nail will give a truer balance as the cone will give the concentric center of the blade which is the pin point axis it spins around while on the mower.

Some blades I had to sharpen had large dents and gouges where a file would take forever so I used a grinder. Long as you balance the blade it makes a difference also.

Thank you. I like the file idea. Especially if you don’t have any other tools.

Angle grinders with a 120 grit flap disc works perfect. Removes very little and the perfect angle is easy to get. It's very quick and does a great job. Been doing it for years !

Iam a fan of work smarter not harder, ive used both pro level blade sharpeners and angle grinders. pro level sharpeners, no average joe with 2 or 3 acers will ever buy, all you need is a blade balancer and just a little bit of experience with a angle grinder and you can do just as good. use a file afterwards if you want it to be perfect if ur Mowing golf courses this guy it 100% right or buy a pro level sharpener and read the Manuel set up accordingly.

I don't see anyone here commenting on what I consider one of the more critical parts of the blade: starting with the part that's visibly worn the most. Your edges on the blade are rounded off. Do you know why they're rounded? Because that's the part that hits most of the grass, and so you're still smacking the grass with a rounded edge. Square it off and make it sharp to the edge. If that involves too much material removal, then get another blade and it comes with that perfect square edge at the very ends. Maintain that edge, that is the first thing that hits grass and it is why it wears the most. It is the most critical part of the blade and the difference is visible.

File works great

That balancing trick just blowed my mind! I was expecting some complex tool to do the job. You just got another subscriber with that!

25 years in commercial lawn care running mowers for 50 to 60 hours a week and every blade was sharpened with an angle grinder and it doesn`t destroy the blade. It does take plenty of practice to be able to do this properly but that comes down to the person, not the tool.

45 years ago my family had a lawn service in south Florida and this is the way I sharpened all of our blades, one set for every other day. Two Grasshoppers ZTRs, two Bobcats push mowers and two edgers. All by hand with a file and I still do that way today.

Nice concise video. Thanks.

My pap taught me how to use files when I was a kid and I still use them often. But, I also know how to sharpen with a grinder. Is does not ruin your blades if you take your time and pay attention to what you are doing.

Angle grinder flap wheel bench vice gloves safety glasses nuff said!!!

There is a jig called the Yellow Hornet mower blade sharpener that will hold your angle grinder at the proper angle and allow you to sharpen your blades properly. Instead of using a grinding wheel, you use a flap disk 40 to 60 grit. Does an amazing job on sharpening blades.

Thank you for your tips amigo. God bless you.

Thank you, file works great for I.

if checking the balance is so easy then using an angle grinder to sharpen the blade isn't going to be an issue is it ?

I learned to hand file when I was young growing up on a farm w/machine shop. I will sometimes do a quick hit with flap disk on an angle grinder and its fine, but hand filing is my preferred blade sharpening method; much better control and superior edge. I also don’t think it takes any longer, maybe 30-45 seconds per cutting edge; about 5-8 file passes. By far the longest part of the job is lifting the mower and removing the blades, actual sharpening is quit quick.

“you’re not shaving your face with this thing…” speak for yourself. ❤

Thanks so much you are correct but I use bench grinder if the necks on the blade is large occasionally although file doesn't remove much metal. I will definitely stick to your advice.

I just subscribed and watched a few of your videos. I like how you roll. Good luck with your channel. I’ll be watching. Thanks.

Great tip about balancing the blade after you are done with the sharpening

I’ve never really had a need for for an angle grinder (although I’ve been looking for an excuse to get one😬) and have always used a file. It’s fairly quick and easy to maintain the original angle.

I was always taught the width of the angle on the sharpened part should be twice the thickness of the blade itself for a reference point to keep your angle in check sharpening, I sharpen way to many blades to do it by hand, use a angle grinder and hold it against my body and keep a consistent movement back and forth to keep the angle while watching the angle being sharpened, also I check the blade before sharpening after cleaning to see which side is heavier for a reference before I start sharpening

I have a grinder but I use a file. I don't due commercial landscape so maybe its different if you do. I like the control I have with a file, with a grinder is will be off but not enough that it wont cut. The main reason for me is the metal shaving, I hate grinder with a passion when it comes to shooting metal shaving everywhere. With a file I can control it better.

Thanks for the balancing tip , i've been cutting the grass for a small Park {2/3 acres} for 14 years and was never successful balancing on a flat bar edge .

Excellent video. Thanks

You can use an angle grinder with the correct abrasive. This could have be achieved with a Flap Wheel Abrasive or a Sanding Disk. Check your balance the end that dips will need a little more sanding till it no longer favors either side. If you need Heavier Angle Shaping use a bench grinder on both ends. Then balance with Flap Wheel Abrasive or Sanding Disk. 👍 Always use Safety glasses and tools you are comfortable with using.

Balancing the blade by using the centre hole and a glass marble or steel ball bearing and placed on a hard surface gives very accurate feedback.

I have used my angle grinder to sharpen my mower blades and my friends blades for YEARS and balance them with a cone balancer and have never had an issue. It's a freakin lawnmower!!

I use my table top belt grinder if Im being lazy but i do enjoy the old fashioned file.

When you use a file, drag the file against the sharp end, not towards the sharp end. Also, instead of a grinder use a belt sander; you can hold the flat angle much easier than with a grinder

I think this guy just learned that he really can sharpen a blade all on his own, and now he feels he has to tell the world how to do it too. And with all his newfound experience, tell you what you are doing wrong.

Finally a smart guy ..........................

Great advice on the hand file. One of the most popular master machinists on YT uses hand files all the time.

Great Video. Thanks for sharing your Knowledge. I'm a retired Pro Musician and I guess I'm a bit embarrassed to say my Wife knows way more than I do about anything to do with house repairs and upgrades. I'm kind of ok at pushing the Lawnmower. LoL. So I'm looking forward to learning as much from you as possible. Stay safe. 😎

Another nice video...I file my blades...so simple and effective...

I love it when I sharpen a new blade and first mow out waaaamo you catch a small piece of a branch and hear that lovely sound of blades being dulled in your mower.

My 2011 troy bilt riding mower was vibrating itself apart including 2 broken motor mount bolts. I replaced the blades before a 3rd bolt broke and everything is fine now running smooth like a new mower.

Ill one up you and say that I use a 2x72 belt grinder then a file lol. But I also sharpen multiple sets for 6 mowers at a time. I will add that you should pay extra attention to squaring and sharpening the tip of your blade. 90% of your cutting happens in the first 1/4-1/2 inch.

Files are effective, efficient and will produce great results with minimal damage to the blade ….. or oneself!

Just did mine this way. Simple, fast, and easy. Working your arm muscles for a couple mins isn’t that big of a headache and probably a good idea.

Great tutorial. An angle grinder used properly will not destroy your blade. I like to use flap discs that don’t remove tons of metal it’s more or less a sandpaper disc.

I've been using a grinder to sharpen my blade for over 30 years. A flap wheel is probably best. I have never ever balanced a blade and have never had bearings go out in the motor because of it.

From a safety standpoint he needs to put a handle on the file tang to protect his hand. I've used angle grinders, bench grinders, and files. Depending on what shape the blade is in determines what tool I use.

Excellent balance tip with the nail.

I have never had a blade that good to start with.

An angle grinder puts the best edge on my blades 😉