Any hardware store should grade 5 or 8 bolts, whatever it is... I wouldn't really be concerned with that though. Just run a die over it if anything. I wouldn't even waste the time.

 

My only major concern would be screwing them into the hub and causing any damage to that ($$). I will try to find some grade 8 locally (great idea thanks), and take it from there. If not then I wil run a die over them.Its just crazy to me they they all broke/stripped in the same location on each bolt. Any ideas what would even cause that?

 

x2 on local hardware store.. Our little hardware store in my area has the grade 8 bolts and washers to match..

 

Agree just get new bolts and double check depth before putting a wrench on it.

What happened... best guess somebody started the bolts on that side, forgot to run them in and tighten them and drove a little bit. You might look for witness marks inside the axle flange holes where the threads dug in.

 

It could have been somebody's sad approach to discourage loosening. They aren't so bad. If you have trouble finding replacements, just run a die over them and re-use.