I have a situation where I want a stand-off to maintain electrical contact between the PCB and the chassis it's attached to.
My question is, what's the best material and finish for this application?
I see RAF has options of aluminum (unfinished), aluminum (clear iridite), stainless steel (unfinished), and stainless steel (chrome/nickel finish), which I would expect all are conductive surfaces.
Which one will have the best reliability?
Are there any material compatibility issues with any of these choices (like causing corrosion when in contact with the PCB)?
Are there better options I haven't mentioned?
Edit Additional information: This system will have to pass rigorous environmental qualification including (IIRC) a few hundred hours in 85 C / 85% RH. It won't have to pass salt spray or any other corrosive chemical stresses.