Shear Bolt vs Regular Bolt

[MikePA]

I stopped at my local TSC to buy some 1/2 x 3" Grade 2 shear bolts for my Brush Bull rotary mower. They didn't have any and the salesman said, "All the guys are using regular bolts of the same size." So, I went over to the fastener section. They had Grade 8, Grade 5 and Steel bolts, according to the labels on the drawers. No Grade 2 bolts. Is it OK to replace a shear bolt with a regular Grade 2 bolt?

[RobS]

Mike, stick with the grade 2 even if you have to go elsewhere to find it. The higher grades will be tougher and may not shear when they need to. That could result in damage to your PTO driveline. As I recall, grade 2 will have NO markings on the head. The other grades will have various raised marks forged into the bolt heads. Hope this helps [img]/w3tcompact/icons/smile.gif[/img]

[Spencer]

This is out of my Bush Hog Rotary Cutter Manual.

[MikePA]

Thanks, Spencer and Rob!

Do either of you know if there is a difference between a Grade 2 bolt and a Grade 2 shear bolt?

[Anonymous Poster]

<font color=blue>...if there is a difference between a Grade 2 bolt and a Grade 2 shear bolt? ...</font color=blue>

Yep... the word shear...[img]/w3tcompact/icons/smile.gif[/img]

Actually some "devoted" shear bolts will have a "groove" cast into the bolt...

[MikePA]

The shear bolts on my snow blower have the groove, two of them I think.

So, is it safe to replace a Grade 2 shear bolt with a Grade 2 regular bolt?

[jasonf]

On my snowblower there are 2 shear bolts for the auger and 1 for the fan. The shear bolts cost around $6 each, and I am always going thru them. I use the grade 2 bolts (which the original shear bolts were) and use my lathe to make the grooves in them. You could also make the grooves in them by chucking the bolt into a drill and then hold a file to the bolt areas that you want the grooves to be. (A dremel works even better to make the grooves). I make up 20 of them in the beginning of the snow season and they cost a few cents each vs $6. BTW I always add 2 to the number of hash marks on a bolt to get the grade. 3 hash marks on the bolt head is a grade 5, 0 hash marks on the head is a grade 2. I find that if you don't make the groves in the bolts they are harder to drive out of the shaft after they shear,[img]/w3tcompact/icons/sad.gif[/img] if you do have the grooves they just pop right out !![img]/w3tcompact/icons/smile.gif[/img] Hope this helps.