I'm repairing 3 metal bi-fold doors for a friend. I can't tell who the manufacturer is but they appear to be an exact match for the doors in your video. Mounting holes are 5/16". My only problem is that the threads on
21-001 Pivot Assembly are formed and not die cut (like the original assembly) which makes them larger than 5/16" diameter. This non-standard thread isn't a problem for the sheet metal nut but the threads won't fit into the mounting hole. I plan to use a small hand reamer and open the bottom mounting hole just enough for clearance.