Joe, pls understand I'm not questioning anyone's voracity or contribution here, I'm just flummoxed and questioning as we all are!
The threads on a "SS" backend do develop the grey matter.
It occurs to me that maybe we should not assume that the male threads on Ti backend are titanium. The clip ring is not, that's clear.
So, I just grabbed a refrigerator magnet and it attracts the clip, ring, temp dial AND male threads on both the SS and the Ti Hopper backends (does not attract the clicker). This is a different ballgame, I believe, and I only took HS Physics. My understanding is that high grade SS is not attracted to a magnet. SS refrigerators don't accept all those cute refrigerator magnets! Yet, what I assumed was SS clip ring and clip is attracted. Btw, the brass colored battery contact is attracted to the magnet also!
At this point I have to disclose that I had two huge teeth pulled about 2 hours ago and I'm using a multi-pronged strategy to relieve the 'discomfort'. This is to say that this magnetism stuff if beginning to confuse the crap outta me but I'm gonna hit 'reply' anyway.
False assumption by me #2 - I was thinking all the threads we're Ti...
The back-end male threads seem to be SS. The female threads are definitely Ti.
Similarly, with the front end the mouthpiece is Ti, maybe the sleeve around the oven is SS too. Mine has hairline scratches that don't look Ti-esque (had a few from the box new).
None the less, Ti, Ni*, Al are all prone to galling, which I understand is the molecular shaving as like on like materials are grinded over each other. It's the principle utilised in cold welding. So it's worthwhile to clean either model GH, so the threads don't chew up and fail (there have been quite a few reports of this already, probably a mixture of this normal degradation and machine quality/tolerance^, mixed with harsh user conditions)
*ferromagnetic, thus if clip thread is attracted to magnets and is SS it has a high nickel contact so black grit city (Trying to clarify this and I think this isn't correct.. Apparently nickel makes steel non-magnetic by creating austentite structures)
None the less the SS will wear better than Ti but will not be impervious to galling
^the threads are really fine and close fitting which will mean lots of surface contact and travel.
Also if the Ti is SS on Ti, that might explain the grainy feel compared to the smoother SS on SS threads.
PS hoping for a swift recovery from brutal surgery!