I've seen lots of these vids, but never one as detailed. This illustrates why a BH costs a bit more than
the average run-of-the-mill rod. That machinery has to cost a good bit of coin, and the workers appear to be pretty darned skilled. Properly trained techs don't come cheap, not here and not in S. Korea. They ain't flippin' burgers in that plant, that's for sure.
Best to turn on your "CC" closed captions to know what the narrator is saying.