Unless there are nylon inserts...Or don't bother, as the doors will already be electrically connected to the container via the substantial metal hinges. (unless the door comes off the hinges, but if that happens, bonding it to the container will be the least of your problems.)
I'd use braid, or tri-rated, ordinary 6491X won't like the repeated flexing.
Briad is what I thought was best. Recommend any in particuar ?