Maybe Chinese. Still, each bolt, nut, et al, must pass the Navy and the Shipyard’s inspection process before being used.
Corruption, the hallmark of union workers.
I doubt the average reader has any idea just how demanding the testing is for materials used in a nuclear sub. I worked in the pre-test lab at a shipyard that was building four such subs, in the early 60’s. Every single piece of pipe, each fitting, every valve, everything that was to be used in the subs was brought into the lab and tested under conditions as near to on board conditions as possible. It was a huge part of the sub building program. This was the days before computers had worked their way into every facet of business life and my job was to record by hand each and every piece that was tested, when it arrived, who tested it, the outcome of the test and who it went to after testing. If an item failed the job got worse, much worse.
I still have nightmares about not being able to find some tiny little valve that was misplaced!