I've read on Miller's welding forum that the Smith AW1A torch compatible AW201 tip(for acetylene) for example, has a mixer with 1/4"-28 TPI internal(female) threads that mate with the copper tip.

As Smith mixers seem to be mostly identical other than the number of fuel inlet holes, I'm wondering if most of the Smith tip mixers 'share' the 1/4"-28 TPI internal(female) threading for the various copper tips and threaded tip tubes.

[ Questions ]
1. Among those that use a Smith AW1A torch with an AT61 'Threaded Tip Tube' (for LP gases), has anyone ever 'unscrewed' the copper 'Threaded Tip Tube', detaching the copper tube from the mixer?

2. Regarding the Smith AT61, can anyone confirm if the mixer's internal(female) threads (or the threading on the copper tube that mates with the mixer side female threads) are 1/4"-28 TPI?
* Note: I'm aware that the flame-side male threading on the tube is 1/4"-32 TPI. I'm trying to find out the type of threads inside the mixer that mate with the copper 'tips' & 'tubes'.

Jihoon Jo