The wonders of threadology!
There is the crux of the matter, our system has a thread for every purpose whereas the metric system doesn't. ( unfortunately should be had not has as most are now redundant).
Seem to remember vividly a TSR2 accompanied by a Lightning either side coming over our school in Blackpool at low level, so it must have originated from Warton for its flight.
Valiant must rate as a blunder, not many built and those that were had tail failures.