shear bolts B2782 snowblower

[Chilly807]

I went to get a couple makeshift shear bolts at Tractor Supply Co on a weekend when my dealer was closed & when I grabbed some low grade bolts, the clerk there told me that I had it backwards - that low grade would "give" and flex rather than break when it should and said I needed grade 5 or 8 that - being more rigid & inflexible - would snap when they should. Can someone clear this up for me?

I'm thinking you're right, grade 2 is fine for a shear bolt. Grade 8 is a much stronger bolt, I've never seen them "properly" used in a snowblower.

I'm not saying it's impossible, only unlikely.

Chilly

 

[JTPass]

I have a question...What is the purpose of the groove on the auger shear bolt for the B2782 snowblower?

 

[lakeside]

I suspect the groove is there to create a weak point. Perhaps even a grade 2bolt is too strong for that type of machine. Just a guess though.

 

[ptrotter]

I have always been told that grade 8 bolts are better as shear bolts as they are more brittle than lower grade bolts and will shear better. Lower grade bolts have a tendency to bend and stretch rather than break. I believe that higher grade bolts are stronger in tension, but not as strong in shear. The 2782 has 2 different shear bolts, the auger bolts with the groove and the other on the shaft that Kubota specifies as a standard grade 8 bolt. I haven't looked closely at the auger shear bolts from Kubota to see what grade they are. I have used grade 8 bolts as shear bolts on my larger rotary cutter and have had no problem with them, they shear off nicely.

 

[Kubota 2350]

My front mounted snow blower on my Kubota 2350 calls for grade 8 in the rear rotor, and grade 5 in the augers.

 

[StrangeRanger]

My front mounted snow blower on my Kubota 2350 calls for grade 8 in the rear rotor, and grade 5 in the augers.

They may call for grade 8, but that's probably why they have the "special" groove in them, to create a weaker point???

 

[radair]

...I believe that higher grade bolts are stronger in tension, but not as strong in shear...

No, this is not true.

 

[Gomer]

I have a 900ft driveway and live in west Michigan and use said blower on my B2630 so I think I qualify as having some knowledge on this subject.

I can tell you from experience that for the back blower, grade 2 bolts will sheer just with the snow load, grade 5 will last a little longer, and grade 8 is what comes on it and what Kubota sells for replacement and will sheer with wood or dog nylabones.

 

[Chilly807]

Well, whatever the manufacturer calls for should be what goes in them.. quite often we like to second guess them based on our own experiences.

Chilly

 

[Erallain]

I have 2 shear bolts in front of me. #1 has a letter N at the 12:00 position. #2 has letters YHC at the 12:00 and hash marks at the 2:00, 6:00 and 10:00 positions. So reading the previous posts..am I correct that #1 is a grade 2 and #2 is a grade 5? Should I use the grade 5 for the fan or the Grade 2. Thanks.