As a 10 time Burning Man participant who builds a LOT of projects and always has a need for stuff you can't find at your big box home improvement stores McFadden-Dale is a godsend. If the big box places don't have it and I don't want to wait for the big brown truck to bring it 2 days later, McFadden-Dale Industrial Hardware is on my short list of places I go to see if I can find whatever crazy thing I need locally.
And while they don't have everything, they carry enough that I can usually find something I can improvise with. From O Rings to bearings to wiring to specialty tools, they have a lot of the stuff I need.
That being said it can be a pain in the rear to find out the price on some things until you get to the register. But if you need help it may take a minute to find someone that's not busy but they will take the time to help you.
I'm only going to give them 3 stars though because the lack of clear pricing is something that annoys me to no end. It's not that hard to make prices clear and easy to find. Until that is fixed I'll hold off on that 4th Star. But if you find yourself needing speciality car tools, springs, O-rings, welding tips, trailer wiring, or who knows what else, and you can't find it at the big box store consider stopping here and see if they have it. There's a good chance they'll have what you need