Sharpening lawn mower blades

[jjohnsonElknewbie]

I have a bench grinder and have tried to maintain the chisel edge on my blades for years. However, I've always just eyeballed them and then put on a leveling post to make sure they're not out of balance.

For the landscaping pros out there, is there a jig or other device that you guys attach to a bench grinder to ensure consistent blade angles and sharpness?

 

[Wrench]

I use a 4" flap wheel on an angle grinder and typically need to take a bit from the bottom vs removing a ridiculous amount of material.

The whole process takes me about 5 minutes and produces sharp clean cuts with no noticeable loss in mulching efficiency.

Fwiw, I have been hacking on this blade for 5 seasons with typically 4-5 grinds per year....5 kids to teach how not to use it as a rock crusher.

 

[MallardSX2]

There is only 1 really good way to sharpen them without taking a month of sundays to do it. I sharpen Hundreds of blades a year. It literally takes 1 minute a blade.

Get you one of these:

6 in. Swivel Vise with Anvil and Pipe Jaws

Amazing deals on this 6In Swivel Vise With Pipe Jaws at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Get you one of these:

13 Amp 4-1/2 in. to 6 in. Trigger Grip Angle Grinder

Amazing deals on this 4-1/2In 13Amp Angle Grinder at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Get you a half a dozen of these:

5 in. x 1/4 in. x 7/8 in. Type 27 Metal Grinding Wheel

Amazing deals on this 5In Type 27 Grinding Wheel at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Put you a balancing nail on your workbench and try to keep the blade balanced the best you can.

 

[BuckRut]

Keep in mind that it is a lawn mower and not a rocket ship. It's not a precision machine by any means.

 

[GSPHUNTER]

I just use a file. works for me.

 

[Dos Perros]

My hardware store does it for $10.

 

[IH8Cali]

Project Farm on YoutTube has about an as in-depth video as one would ever need to go on the options available for sharpening blades. As posted above, ye' old flap/grinding wheel disc on a grinder and a vise are pretty tough to beat.

 

[smithmtva]

just remember when you grind them down to make sure you keep them balanced as not to wear on the bearings.

 

[jjohnsonElknewbie]

Thanks fellas, I have a vice and angle grinder as well and have used these in the past. I feel like I have better control using the bench grinder. I will grab one of those flap wheels and give that a wirl.

FWIW, I recently installed a full set of 3 Oregon blades to replace my 60" Kubota belly mower OEM blades. They've been used a couple times, and I'm already seeing some chipping. I'm not impressed with how they're wearing compared to the factory blades that lasted more than 10 years. YMMV...

 

[jjohnsonElknewbie]

I just found this for guys that prefer a bench grinder and its genius. Obviously you need to adapt to the angle of your blades, but very cheap and easy. Only thing I don't have is the plastic protractor and I can get one of those at Dollar Tree for $1.25.

 

[Rob5589]

I just use a file. works for me.

Same. Pull the blade, vise it, file, back on. 10 mins tops.

 

[huntsman22]

I didn't know there was any other way than files......

 

[ODB]

I didn't know there was any other way than files......

Yup. Count the strokes, be as consistent as you can and motor on…

 

[CJohnson]

Learn something new everyday I guess. My dad had a lawn care business for 30 years and every Sunday during mowing season he personally sharpened the blades on all of his equipment using a bench grinder, no gloves, and an OSHA-approved squint.

I’ve dabbled in knife-making and I think there’s probably a pretty substantial impact on the bevel angle and durability. That may explain the difference between the factory and after market blades @jjohnsonElknewbie

 

[MallardSX2]

You must be using some shitty blades if you can file them….lmfao

 

[GSPHUNTER]

You must be using some shitty blades if you can file them….lmfao

Any carbon steel blade can sharpen by hand with a file. I have done it many years on various mower blades. If you are talking titanium that may be different, though I have never sharpened one made of the material.

 

[5MilesBack]

I tried to file mine last year and got nowhere with it, so pulled out the grinder. But I also mow a 1/2 acre that has a bunch of ponderosa, pinon, blue spruce, and fir and no matter how much I clear it, there's always some surprises hiding in the weeds and grass that I hit.

 

[Wrench]

The jagged edge the grinder leaves works for you.....not against.

 

[jjohnsonElknewbie]

Learn something new everyday I guess. My dad had a lawn care business for 30 years and every Sunday during mowing season he personally sharpened the blades on all of his equipment using a bench grinder, no gloves, and an OSHA-approved squint.

I’ve dabbled in knife-making and I think there’s probably a pretty substantial impact on the bevel angle and durability. That may explain the difference between the factory and after market blades @jjohnsonElknewbie

The recommended bevel angle depends on the “expert” opinion and what you’re typically mowing. I found it’s all over the place with some saying 30 and others 45 and somewhere in between. The higher the number the more durability since you have more meat, and it’s also better for the harder cutting brushy weeds. The lower the number the finer the cut but you lose durability with less steel behind the edge.

So for a bush hog a guy would probably want to go near 45 and for manicured lawns closer to 30.

 

[Wrench]

The temper of your blade plays in as well....