bush hog blade sharpening

[fuzzydawg]

Got a question about sharpening: I've always sharpened the blades on my bush hog once a year, never tried to get them razor sharp but just clean off the biggest nicks and get some kind of edge on them. I'm cutting a mix of heavy brush (lots of multiflora rose and small eastern red cedars, plus any miscellaneous saplings that get in my way) along with whatever fescue, ragweed, and other junk that grows in the power line easement. By the way, this is a 5-foot Woods hog behind my L3400.

So a friend who grew up on a ranch told me that I'd be better off letting the blades stay dull, because a dull blade will shatter the stems of whatever brush I'm cutting and the plant won't grow back. He says if I have sharp blades that cut them clean, they'll just spring up again.

Doesn't sound right, but he swears by it. What do y'all do - sharpen or not?

 

[Stumpy]

I do remember reading something that said brush hog blades are suppose to have a slightly rounded edge vs the sharp edge of a lawn mower blade. No experience with that, just saying.

 

[TripleR]

Specs should be in your manual and if you don't have one, check online. I do the same procedure on our Land Pride and Woods, from the manual:

Both blades should be sharpened at the same angle as the original cutting edge and must be replaced or re-ground at the same time to maintain proper
balance. The following precautions should be taken when sharpening blades:
a. Do not remove more material than necessary.
b. Do not heat and pound out a cutting edge.
c. Do not grind blades to a razor edge. Leave a blunt cutting edge approximately 1/16” thick.
d. Always grind cutting edge so end of blade remains square to cutting edge and not rounded.
e. Do not sharpen back side of blade.
f. Both blades should weigh the same after sharpening with not more than 1 1/2 oz.difference.

We cut some pretty heavy stuff and sharpen every two or three years, so the blades are obviously out of spec more often than not.

 

[Stumpy]

And there you go!

 

[GBOUTDOORS]

Take a look at new ones at your local TSC or other supplier. They are not very sharp but more blunt even when new. As said by others they are made to shred ot cut clean.

 

[Bulldog]

I like mine sharp (not like a razor) enough to make a good clean cut in grass. Also to me it seems to be easier on the tractor when the blades are sharp. Depending on how much cutting I do I may sharpen blades 2 or 3 times a year. I prefer to try and maintain a good edge instead of letting the get as dull as the side of your finger and then try to sharpen them.

 

[Eric McCarthy]

Yep I agree with Bulldog.

 

[yesmar74]

What Bulldog said. They'll get a blunt edge soon enough.

 

[tempforce]

i think of a pair of scissors, when i maintain the edge… just my 3 cents...

 

[Gundoctor]

When I put new blades on I only cut grass with them. If I want to cut brush I put the old blades on and have at it.

David Pidgeon
New Haven, Vermont

 

[Bluegill]

I agree with Bulldog also.

I sharpen mine when they need it...

 

[Sledge]

I've got a bush hog and don't want to invest in another machine, so if the blades are sharpened a little will they cut grass better? I need to cut brambles and then the grasses etc that hopefully grow in their place.

 

[Dave_eng]

I would like to bring some simple physics facts to your attention which pertain to the difference between a lawn mower and a brush cutter.

The brush and light tree cutter blade is impacting something that will not move out of the way as easily as a blade of grass. The blade tip speed of a 7' wide Bush hog SQ84T is 11,500 feet per minute.

Lawn mowers, including zero turn mowers, which have higher ground speed, have blade tip speeds of greater than 16,000 feet per minute and some up to 20,000. The higher tip speed is necessary to cut the blade of grass before it can be pushed out of the way.

You may find your brush cutter does not do the grass cutting job you would like.

Dave M7040

 

[Bulldog]

Sledge, my opinion the sharper the blades the better they do cutting in grass.

 

[Sledge]

Thanks both. Am much the wiser.