plunger tube thread size

[Adtrac]

I am wondering if someone would be able to tell me the internal thread pitch and  size on a BSA  A10 Plunger  tube , ie where the caps screw into .

[MikPowl]

Measuring the threaded boss on my plunger column fit/remove tool, the thread guage says 20tpi pitch.  Eyeball measurement against a ruler puts the size of the boss at 7/8".

[muskrat]

G'day Adtrac.
Mik is correct.
https://stainlessclassics.co.uk/product/bsa-plunger-suspension-top-cap/
Cheers

[limeyrob]

Interesting that you can get taps and dies:
https://www.tracytools.com/product/7-8-x-20-tpi-bsc/

[Rex]

Tracy do a lot of very obscure stuff to be fair.

[muskrat]

G'day Rob.
I got a 1/4, 5/16, 3/8 set off them probably 30 odd years ago.
Cheers