I bought a package of 4 shear bolts for our 5 foot cutter and they appear to be grade 2 bolts. Better to shear a bolt than to bust a gear box.
 
I use grade 5 bolts in my crimper and my baler.
They shear before breaking anything. I wouldn't want something softer, and I don't wish to try the grade 8s.
 
I use a grade 2 bolt in my King Cutter 5-foot hog. I'm cutting mostly grass and weeds with the occasional sassafras or persimmon sprout.
 
Grade 2 bolts wouldn't last me five minutes.

Grade 8 (if I could get them) would defeat the purpose of having a shear pin.

So Grade 5 it is.
 
I use Grade 5 in my brush hog. Since I put (2) spares in a box mounted to my fender along with a couple of wrenches, I haven't busted a single one. :eek:

Although, I thought I busted one the other day when it got quiet behind me and I looked back to see nothing being cut. Turns out the nut came off and the bolt fell out. Both laying on the deck.

A farmhand at a horse farm where I board my horse was tired of replacing Grade 5's in a post hole digger so he put a Grade 8 in them (twice). Had to put a welder to the auger (twice). Finally someone explained why you WANT the bolt/pin to shear.
 
I use Grade 5s in my Bush Hog Rebel. The original was a solid tapered pin and is obnoxious to replace if you use the original. also obnoxious to get the center portion of the old one out. I don't think we ever put in a OEM pin on this mower.

jt
 
(quoted from post at 07:19:41 07/07/14) Is it better to but shear pins for a bush hog or a grade 5 or 8 bolts?





If your hog is equiped with a slip clutch and it's adjusted correctly and works as it should you could have a big monel rivet in there and not worry about damage to the drive line.
 
Thanks everyone looks like grade 5 it will be I would look into getting a slip clutch but it is not my bush hog it is my grandmas
 
You many want to consider that, this is one of the more abusive pto driven implements you can attach to a tractor. Depending on the conditions, what you will be cutting, and or the hidden, unforseen rocks, objects or the worst case scenario, any stumps and all the rest, that it either slips properly via a slip clutch or it shears when it needs to. I saw a very expensive repair with a JD 2020 last year, which I now suspect was an unknown, possibly grade 5 or 8 in the driveline of this old but really heavy duty rotary mower, it destroyed the shaft coupler, and it was a split and complete tear down, for a very inexpensive bolt, pin or slip clutch.

My old Rhino has a shear pin hole in the drive line and I use shoulder bolts with left hand thread that shear, which have nylon line nuts, these will shear before a grade 2 bolt will in the drive line, it will lay both blades down under the deck, with the remains of the hardware, last time it was a hard round rock, that surfaced the last time the field was in crops. The blades are connected to a blade holder that has as stump pan, no doubt those pans can help reduce some impact. I ran a tail wheel through this mower, and though I did slow it down quickly, the grade 2 nor the blade bolts sheared, it did a lot of damage to the deck, another 50 cent pin, that failed, cost a lot more in repairs, should have been replaced, it got past me, new tail wheel, and a bunch of labor to straighten the sidewall of the mower and a bunch of miscellaneous welding to the deck, caught some welds on the blade holder that would have failed, wish that grade 2 or blade bolts sheared that time! Not to mention if it was paying job the down time over a darned 50 cent pin.

I've taken saplings and heavier brush/bushes, starting up high and lowering into them in the succeeding passes, in 12 years with this mower, I have sheared that grade 2 bolt one time as I recall, it does fit nicely too, no slop. I think the best advice is to play it safe, they can do some damage in short order per the above. If you are dealing with a lot of conditions where it will impact and shock load the drive line, don't have a stump pan, I'd seriously consider a slip clutch, make sure it works correctly or get a pile of grade 2's to keep on hand, at over 3K in repairs like the above, and or depending on what you have for a tractor, something to consider, that buys a lot of bolts/pins and or slip clutches.

Another thing, depending on what you are running for a mower, with so many different kinds out there, the book for it may provide the specifications of what should be used anyway, one page in the book for mine certainly helped me avoid a lot of problems, as well as making it perform as designed etc.
 
I read about the slip clutch and heard if you don't use them much they can sieze up we only use a couple times a year and the one place is in a woods with a bunch of trash in it by no rocks
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top