ning
Elite Member
I disagree; my guess is that the geometry is:The break is not at either of the two points of shear, but outside the collar under the nut.
@wirlybird can you post a pic with an unbroken bolt in going through, and one of a broken bolt in the hole?
My guess is that the bolt near the cap is about the right diameter, but the hole in the shaft is larger which allows the shaft motion on the bolt shoulder, and then the other edge of the collar is over threads which are very much not the right diameter (well not after you run it for 5 seconds).
Most likely the mismatch of the shaft hole and the collar hole sizes is mostly ok, but the collar being over threads is definitely going to do the bolt in