no vice grips please....
you run 1 nut down until there are 3 or 4 thread showing, run the second nut down on top of the first one.. Hold the first nut, snug the second one down.. (they are tight against each other)
Now use the second nut to tighten the stud (this will keep the threads all happy)
After the stud is snug (do not make it very tight, just snug) now hold the first nut again, loosen the second nut.. they should both thread right off the stud
It is an error to tighten studs down very far as it weakens the connection and the stud can break off later (now you got a problem)