Shear Bolts, What do you Use?

MrJimi · Aug 21, 2006

I just recently purchased a Howse model 500 RC ( 5 Foot / 45 HP gearbox )and it came with a grade 5. 1/2" shear bolt, this seems to be a little heavy for this unit. What are you running and on what implement for your safety and is it heavy enough or could it be heavier or lighter?
I am running mine hydraulically and I could go with a relief valve in-line.
Darn I wish I could make a poll out of this, oh-well
Jim

dtd24 · Aug 21, 2006

I have a King Kutter 5' with 40 HP gearbox, and directions say grade 2.

RonMar · Aug 21, 2006

Grade 2...

scott_vt · Aug 21, 2006

Im gonna have to cast my vote for grade #2 also

firemanpat2910 · Aug 21, 2006

I have an old JD that I have to use a grade 5 7/16 bolt in.
A grade 2 breaks before it will get blades turning.

ejtaylor822 · Aug 21, 2006

Grade 2 or 3 at half inch dia. with mine which is 6' and rated up to 45 HP PTO. Used a grade 5 once and hit a rock. Made the worst racket and bogged down the engine a little but the bolt held - should have snapped it off like a twig. Ever since then I use the lower grade stuff out of the bins at Lowe's which is rated no higher than 3.

Marcussen · Aug 21, 2006

In have two 5 foot cutters one (agrifive ?) use a 7/16 grade 2 the other (Woods brushbull) a 1/2 inch grade 2. I only have the manual for the Woods and it states "1/2" NC x 3" grade 2".

scesnick · Aug 21, 2006

I know this isn't about snow blowers but that is what I have a major problem with shear bolts with. It is a Ber-Vac 64" and when I run grade 2 pins they sheer pretty much as soon as I start blowing snow. I up graded to grade 5's and even they will shear when I hit clumps of semi frozen snow. I don't want to even try grade 7's but I get sick of carrying a pocketful every time it snows. Any ideas???

Neophyte · Aug 22, 2006

I have a Howse 500 as well. I have been using Grade 2 but I snapped 3 of them today from hitting rocks and small trees. I can understand the rock snapping it but it seems like it should have made it through the small trees (1-2"). I know several others on this board have mentioned using Grade 5 bolts and I may give this a try.

Do you have a slip clutch on your cutter? If so, Grade 5 is fine.

It should also be noted that the Howse Documentation lists a 1/2" X 3 1/2" BOLT NC GR5 HHCS ZINC for the shear bolt. They actually recommend a Grade 5. You can see the exploded parts view at the following link. Click on Z62, which is the shear bolt.

http://www.howseimplement.com/html/300__350_400__500.html

I should also mention that someone borrowed our rotary cutter and replaced a snapped Grade 2 bolt with a Grade 8 bolt. Needless to say, they ended up replacing the gear box.

BB_TX · Aug 22, 2006

I have a Howse 6'. I use a grade 2. Usually shear 2-3 a year.

jinman · Aug 22, 2006

Grade 2...too many to count. They work great!

PineRidge · Aug 22, 2006

My vote is for grade 2

CharlieTR · Aug 22, 2006

I have 6' medium duty cutter. I only use grade 5 since after the first day I used it. I think the bolt must match the hole size, so not a choice there.
I also think the type of cutter matters (Light, medium, heavy duty). My medium duty is rated to cut trees up to 2". If I cut more than than 2" that grade 5 will shear. With gr 2 I got same results as Fireman (break while engaging) and it would break just looking at a two inch tree.

MrJimi · Aug 22, 2006

I just made a phone call to Howse and left a message, still waiting for a reply and the best I can tell from their parts list online? it shows a grade 5
Jim

Neophyte · Aug 22, 2006

Good luck with Howse. Ordering parts through them has been a nightmare. The other part that annoys me about Howse is that they don't even offer their manuals online like most of the other companies. I think having manuals available online is a matter of safety. You shouldn't have to call and order them for $10 each and then wait for several days or weeks.

Soundguy · Aug 22, 2006

You can get gr2 and gr5 in the same sizes.

I've cut plenty of 2" material with my 5' kk and gr2 bolts.

For the original poster.. my vote is for gr2.. unless you have a slip clutch.

Soundguy

CharlieTR said:
I have 6' medium duty cutter. I only use grade 5 since after the first day I used it. I think the bolt must match the hole size, so not a choice there.
I also think the type of cutter matters (Light, medium, heavy duty). My medium duty is rated to cut trees up to 2". If I cut more than than 2" that grade 5 will shear. With gr 2 I got same results as Fireman (break while engaging) and it would break just looking at a two inch tree.

Dargo · Aug 22, 2006

Soundguy said:
...unless you have a slip clutch.

Soundguy

Ah, ha!! There is my vote!!! I got so sick of carrying a toolbox full of grade 2 shear bolts for my 6' cutter that it drove me nuts. I have a 70 hp gear box and I'll mow anything I can push over. There is a guy named Darryl Harris in central KY somewhere (you can find him on eBay by harrisfarmequipment or something like that, and it cost me less than $100 to put on a slip clutch. I adjusted it for a 40-50 hp gear box and I've not had a problem since.

I'd hate to count the wasted hours trying to get the darn little piece of the broken bolt out of a hot shaft sticking out of the gear box and screwing around with trying to line up the new bolts. Grrr!!! Heck, if you have a splined gear box, I'll sell you a 40 hp slip clutch for $50. I bought it to put on my rototiller before I got my tiller delivered. When my tiller was delivered it had a slip clutch on it which I didn't order. When I called to tell them, they just told me to keep it; thus the extra.

sandman2234 · Aug 22, 2006

Mr Jimi,
I guess this post reinforces my phone conversation of last night. Suggested a slip clutch and shear pins as a dual insurance policy for that hydraulic motor. I would try the grade 2 and if they break too frequently, go to something a little stronger.
David from jax

MrJimi · Aug 22, 2006

sandman2234 said:
Mr Jimi,
I guess this post reinforces my phone conversation of last night. Suggested a slip clutch and shear pins as a dual insurance policy for that hydraulic motor. I would try the grade 2 and if they break too frequently, go to something a little stronger.
David from jax

David, in the hydraulic world there is a different approach to this, its called a relief valve in-line.
No its not installed yet and I am drilling holes in beam to bolt trusses to beam, 66 to go