A bolt-coupling was a form of joint. It held hull plating onto the outer hull of an NX-class starship. About three hundred bolt-couplings were beneath each hull section. When Enterprise NX-01 detached a hull section from the rest of the ship in 2152, the bolt-couplings were necessarily first removed by engineering officers from the ship. (ENT: "Minefield") An ultimately omitted moment from the final draft script of "Minefield" involved "a couple of bolt-couplings" accidentally freezing up, causing a delay in the time taken to detach the separated hull section.