US pipe thread for FUTURLINER

[MBfreak]

Hi to all.
Hope this is the right Forum for a pipe thread standard question.
I am involved with the restoration of a 10 kVA genertor made around 1950.
The thread for the electrical conduit is a seemingly standard 2" NPT.
HOWEVER, as far as I can see from thread tables the 2" NPT is supposed to have 11 TPI, which also holds true for a Whiworth standard 2 " cylindrical pipe thread.
But, the thread o the cable intake on the FUTURLINER generator is a 2" pipe thread with 12 TPI. I may have to make a new screw in part with 12 TPI, but can an oldtimer on this forum give me a clue why it was 12 TPI back then?
I attach some pics of the newly sandblasted and epoxi-primed stator parts.

Bst regards

Ola

 

[Possum]

Is it American standard straight pipe at 2" -11.5 thread? Are you measuring the outside of the pipe and getting 2"?

 

[mdlbldrmatt135]

0.....

 

[MBfreak]

Guys.

I measure the outside diameter of the threaded part to be 2 11/32 "or 59,53 mm. This is the correct OD for a 2" pipe thread, be it NPT or Whitworth. And the pitch is 12.
The thread table (A Swedish Karlebo from 1964) available to me states that NPS as well as Whitworth Pipe " 2" pipe thread " is 11 TPI.

So, anybody that has a better/ more relevant thread table that includes this thread, please give me the reference or the link. I have not been able too find it on the www, but I am pretty clutzy at finding things on the web.
Thanks a lot and best regards

Ola