I guess the thread is whiteworth thread ,55 degrees 1 in- 19 TPI or 24 Who may help me confirm standard please
@Koalas 1inch X 19 T.P.I. according to my thread gauge but I'm not sure if it's Whitworth or American National 60 degrees.
There are also B.A, (British Association) BSP (Pipe) BSF (Brit-- Standard Fine) Brass , Pipe and I think quite a few others. (I thought there were at least 49 thread standards ) Try this " International Thread Standards " (I count 53)
Most British threads are 55° Whitworth form; the exceptions being BA (49.5°) and British Cycle which is 60° and usually 26TPI (it's often confused with British Standard Brass which is 26TPI x 55°) British made lamps and lanterns tend to use BA and BSB plus Whitworth Special- Tilley also used some proprietary threads.
