Thanks for the links, VE1BLL. Unfortunately, the outer diameter across the flats is too big for each. 1/2" across the flats for the given thread and thickness I need is very hard to find in stainless steel for some reason. Strange. I'm searching using "jamnut" as a keyword now also.
I am looking for a panel nut with specific dimensions of 3/8-32 thread, 1/2 inch across flats, and 3/32 inch thick to mount a switch in an aircraft's engine compartment. The catch seems to be that I am looking for stainless steel nuts, however the only ones I have come across are either nickel...