Rotary Cutter Sharpen or not to Sharpen that is the question

pokerboy57 · Apr 5, 2011

I own a Howse 5' rotorary mower (A Brush Hog). I've used this to cut down lots of grass and brush . The blades are not very sharp . I was wondering if sharpening these blades is something that other rotary mower owners routinely do or not..

thanks,
ray

Ray_Fort_White · Apr 5, 2011

I had to sharpen the blades on my rear finish mower after about 30 hours. Seems to me that sharp blades cut better.

Ray

DK35vince · Apr 5, 2011

I sharpen the blades on my King Kutter brush mower once per year.

UnclePaul · Apr 5, 2011

I sharpen blades quite often on my rotary mowers to keep the quality of cut up. I mow mostly horse pastures so the sharper the blades the faster and better it cuts.

k0ua · Apr 5, 2011

In a word, No. One thing to consider if if they are sharp like a lawnmower blade, then the brush will be cut cleanly, and sometimes on an angle if your terrain is sloped a bit, which can leave sharp "punji stakes" for your tires. better to beat them off and leave frazzled stobbs. Also where I mow, it is "rock city" Sharpness would not last long anyway.. Some here will likley disagree, but this is what I do.. Besides if you do take the blades off, I hope your 3/4 impact is working well, you are going to need it.

James K0UA

RoyJackson · Apr 5, 2011

Ray_Fort_White said:
I had to sharpen the blades on my rear finish mower after about 30 hours. Seems to me that sharp blades cut better.

Ray

Pokerboy57 is asking about a rotary cutter, Ray...not a finishing mower.

Pokerboy, this is what Land Pride cutters require:
Do not grind blades to a razor edge. Leave a blunt
cutting edge approximately 1/16 thick.
I just dress mine down a bit...now.

I had been putting a bevel on the blade for years. Just happened a thread on TBN (maybe a year ago) discussed sharpening cutter blades and I went to my manual....shame on me, I had been doing it wrong.

If you have the manual for that Howse, you should see what it says.

As far as frequency, it's every couple years. I only cut about an acre a couple times a year, nowadays.

wolc123 · Apr 5, 2011

A light duty rotary mower, that is mostly cutting grass and a little light brush, should be touched up now and then. I dont remove the blades to sharpen. Lift it as high as it will go with the 3-point, then lower it onto some blocks. Turn the tractor off while in gear and take the keys out. Crawl under with a 4-1/2" agle grinder and sharpen the blades at about a 45 degree angle. Leave a flat aprox 1/16" thick across the face to avoid the "punji sticks" or whatever you call them. A blade so sharpened will make a neater cut on grass for sure an possibly use a little less hp and fuel to get the job done. The longer you use the mower, you will recognize by the grass-cut quality, when it could use sharpening.

Marveltone · Apr 5, 2011

My Woods HC54 manual says: "Do not sharpen blade to a razor edge. Leave at least a 1/16" blunt edge." Their website continues: "It is not necessary to have a razor sharp blade. This will only decrease blade life." I would imagine most other brands have similar guidelines.

k0ua makes some good points. I've noticed the trees and brush I've mowed have frazzled ends, rather than sharp and pointy. Perhaps that's why my relatively thin turf tires have survived (so far) my field mowing.

Joe

k0ua · Apr 5, 2011

wolc123 said:
A light duty rotary mower, that is mostly cutting grass and a little light brush, should be touched up now and then. I dont remove the blades to sharpen. Lift it as high as it will go with the 3-point, then lower it onto some blocks. Turn the tractor off while in gear and take the keys out. Crawl under with a 4-1/2" agle grinder and sharpen the blades at about a 45 degree angle. Leave a flat aprox 1/16" thick across the face to avoid the "punji sticks" or whatever you call them. A blade so sharpened will make a neater cut on grass for sure an possibly use a little less hp and fuel to get the job done. The longer you use the mower, you will recognize by the grass-cut quality, when it could use sharpening.

Agreed, if you are mostly mowing tough grass/weeds, then by all means a sharper blade will do a much better job, and take less HP. But I was thinking mostly of busting brush, and small "trees" and grinding up my rocks:laughing: Of course a finish mower needs a fairly sharp blade, to do a good job.

James K0UA