Originally Posted by Irelands child
Unfortunately many bolts found in the big box stores, ACE, etc are Chinese. Now, if you can trust their QC as well as steel quality..........go for it. If I need a ho hum Gr 5 for a non load bearing joint or for safety, I'll go to Tractor Supply and for a very few more cents will get their Gr8 and "assume" that it at least meets Gr5 specs. If I really need the strength, I'll go someplace like Fastenal or order from ARP.
I have put some serious torque on the grade 8 bolts that I have gotten from Lowe's and haven't been able to distort the threads or break a bolt yet. Local Smith Fastener or Fastenall is cheaper, but is a longer drive, so for just a couple bolts, I go to Lowe's .