barrel to cyclinder head thread

[freefly103]

While taking of the cylinder head off the barrels, I managed to unscrew the large stud from the head (instead of the nut from the stud) i.e. the barrel nut remained on the stud and the stud came free from the head.

Now I need two nuts to screw onto cylinder head end of the stud, so I can remove the barrel nut.

Anyone know the thread please?

Many thanks.

 

[L.A.B.]

3/8 x 20 BSF.

 

[pommie john]

3/8 x 20 BSF.

Surely it would be Whitworth if it's threaded into the alloy head?

 

[L.A.B.]

3/8 x 20 BSF.

Surely it would be Whitworth if it's threaded into the alloy head?

No, it's BSF. It would perhaps have been better if it had been coarser Whitworth thread.

commando-head-stud-thread-t24331.html#p320101

dang-pulled-out-head-stud-suggestions-please-t12741.html

cylinder-head-stud-what-thread-t361.html


http://www.oldbritts.com/nor_comm_73_2.html

20 NM24389 Stud, 3/8 x 26 x 20, Cylinder Head

 

[pommie john]

I stand corrected.

I'm quite surprised to hear that. Norton don't seem to have worried about using many different threads all over the bike, I wonder why they didn't use a coarse thread here.