To be perfectly honest I’m still printing my parts, so I would not be able to give you an experienced answer on that.
The wall thickness on these SS tubes are 1.6mm thick. I wanted them thicker but nothing else would do.
So that is another reason why, on a first build not go any bigger in Axis length then what I have. But
this tube being 316SS does help in the rigidity.
Here is a link to what I have found to be available conduit here in Australia :- http://www.williamsmining.com.au/Williams%20Mining%20Catalogue%202013.pdf