DON'T use stainless......
yes, I know, every-one does it, becouse stainless is shiney and dont go red.....
But what makes it stainless is a high nickle content, whcih also makes it effoff hard.
and they still 'sieze' even if they dont rust...
at which point, they are a bloomin night-mare to get unstuck / out.
Many MANY years ago, I entered the frey of school-boy trials.
after trasking the bike a couple of times in my endevours, I pulled the thing completely to pieces to get it straightened, and fix the other bits that were broke.
I had this wonderful 'brain-wave' that if I put it back together will a big bucket of stainless nuts and bolts, it would be a lot easier next time!
Oh how WRONG I WAS!
Next time.... which wasn't actually very long after.... only a season or two...... those pesky nuts and bolts were siezed solid.
Where they went through exotic magnesium engine cases, this made them nie on impossible to remove..... especiallu if they are cap head's!
They defy drilling, and if you do manage to make a hole in one, they defy any known easy out.
And in the attempt at drilling, hack-sawing ir grinding, its usually the softer mild steel, aliminium or magnesium the drill bit, hacksaw blade, or grinding wheel finds its way through......
Use mild fasteners for anything that needs securing tightly; on things like body panels, use zinc coated.
where steel goes through ali, IF YOU CAN use nylon (like number plate) screws; they offer zero chance of electrolytic corrosion.
Where you cant, use steel, but use a plastic washer and make sure that the hole its going through is over sized. (You can use a pair of plastic washers and a rubber O-ring if you like)
Dont know that ptfe does much, its a sealant, intended to tear as its screwed in and fill gaps in the thread, if it works as its supposed to it wont cover the steel and provide a barrier between steel and ali, and in all liklihood not much of a baffle against a cell being set up when water gets in.
Use grease / coppa slip or WD40 to keep water out of the joint.
