Ive always had really good luck with Fastenersuperstore until now. I got a box of ¼-20 lock nuts that were made wrong, they destroyed the bolts trying to put them on. Their website says they pay return shipping for issues that are their fault and I would think selling nuts that cant be used would qualify as that. They refuse to send a return label to to issue a refund even though the photo clearly shows the nuts are tearing up the bolts.

Always has the best deals!