I'm going electric!

[Yummyrum]

I just pulled out element and thread is 32mm or 1 17/64 “
So yeah 1 3/8” should be fine so long as you can centre the nut on it while soldering . 1 1/4” would also be OK . Just the bigger you go , the less solder you have under the nut

Working with metal is very new for me. I was thinking that 1 and 1/4 might get solder into the threads. If that's not an issue though, I'm guessing that it would bond more strongly with a 1 and 1/4 inch hole.

Thanks again!

Sorry , I messed up . Freedom units are fuzzing my brain today .
1 1/4” would be too small .

1 5/16” would be better .

[MooseMan]

Oddly enough, it would appear that there is no dimension on a 1 inch stainless steel locknut that is actually 1 inch. (I'm assuming that the 1 inch refers to the internal diameter of the pipe this nut is supposed to fit on). In any case, the internal diameter of the nut is about 1 and 13/64th of an inch. So I'm thinking that a hole that is 1 and 3/8th of an inch in the side of my still should be the right size.

Am I right?

Yeah BSP thread sizing doesn't make sense to the modern brain at all, but they still use it.
Do a quick Google and you'll get it.

Do you have the ability to create a small shoulder in the nut?
Ideally you could then drill the hole in the keg to suit, and the nut will seat into the hole perfectly, this would create a very strong joint too.