I have realized that s41s is too heavy for edc and tail knurling is too agressive so I started to swap parts.
I have black astrolux s1 with 18350 and 18650 tubes and s41s with short tube. (All from banggood). I wonder but all threads are different.
S41S short SS tube have 21.8mm threads OD. Cant enter S1 internals.
S1 short tube fits s41s but threads OD is 21.6mm.
S1 long tube goes trought threads in s41s head and tail because threads OD is just 21.3mm.
Im not saying about length difference, waterproof and etc., just threads fitting.
Can anyone measure bare a6 tubes from BG?
Anyway (I have already posted this in S41 thread when S41S was just in our dreams) SS bezel+copper head+aluminium tubes seems much prettier as EDC than all cu+ss light. Tail can be both from alu or ss but I think that p60 light have best solution when SS is only used for the top part of tail, while main material is alu.