Cheap hardware and fictitious grading of it has been a problem for years.... I try to keep on hand what I need, usually order from Gardner-Wescott, when I have to get something locally I pay the extra $$$$ and go to Fastenal. I do use the cheap stuff for mockup and some fixtures, but the final assembly hardware is always the good stuff!!!!! Once upon a time had some bogus grade 8 bolts that hold the steering arm to the spindle on a sprinter break, cost me a junked car and one heck of a wild ride!!!! Never again!