Buy snowblower shear bolts appropriate for your make/model machine. Any good
H/W store or small engine service place should have them,

I've used the hardware-store shear bolts; they actually shear a little
easier; they have small grooves in them.

They have definitely sheared; usually a central part is in the center
shaft and must be pushed out.

I HAVE jammed a couple of rocks; I WANT the pin to shear then! But I've
had the regular 1/4" bolts shear biting into a semi-frozen drift or
embankment.

Anyone have an idea what the ratio of shear torque would be for a 5/16"
mild steel bolt VS the 1/4" ones?? Is it proportional to area? Or some
other factor??

I'm realizing that the 'worn hole' thing may be significant; I think I
only sheared one the first season.. 5 years ago. I've moved a lot of
snow since then!!

--
Regards, Terry King ...In The Woods In Vermont

The one who Dies With The Most Parts LOSES!! What do you need?