Hi I’m at my wits end trying to find a lamp adapter for my friends French (I think) lamp. It has a larger thread on the lamp to the thread on a normal bulb holder. I ordered a French thread adapter which would have been perfect if it was 10mm but it’s not it’s 1/2 inch. Any ideas on where I can get a 1/2” one???
If it is French, it is likely to be metric, not 1/2".
Though not definitely.
How accurately can you measure it, and can you measure the thread pitch/TPI?
That way, it can be matched up to the known thread sizes.
PG7, which is a metric European electrical thread size, is 12.5mm OD and 1.27mm pitch.
1/2" conduit would b 12.7, OD, and 18tpi.
25.4/18=1.41mm, so close to the PG size.
But, the 1/2" thread is not forced to be a conduit thread, hence why I have suggested accurate measurement and measuring the TPI/pitch.
Diameter with a vernier or digital vernier, and the pitch would need to be by elimination. You will get an 18tpi pitch gauge and probably a 1.25 and a 1.5; you might get a 1.27 as it is a tenth of 1/2" in mm.
You may get a 1.4 (probably) and a 1.45 (possibly), but a 1.41 is doubtful.
