alot of advance auto stores have really nice hardened nuts, bots, etc.

not many people know this because they keep them in the back of the store with all the parts. i would check them out, it might make a shorter trip. they should have a big red cabinet in the back that is filled with these. i get them from advance now that i found out they had this stuff. they have all different sizes and grades. just talk to someone who looks like they have worked there for more than a day (if that person exists)