Michael,

From what you wrote you obviously know that it is not a good idea to "mix metals" as this leads to galvanitic corrosion. Most commercially available hangers are stainless steel (though you can purchase plated steel hangers that are intended for indoor use but are used outdoors in some areas - but not in the BV). If you are replacing a missing hanger, use a stainless nut (and washer) if the stud is stainless. If the stud is non-stainless, then it probably doesn't matter if you use a non-stainless nut or washer. If in doubt, use stainless.

For new bolts placements, please use only stainless bolts, nuts, washers and hangers (not necessarily Fixe brand). Hilti bolts are preferred by several local buiders because they seem to "grip" better when they are tightened. However, other brands are perfectly acceptable (and slightly cheaper). Be careful buying "stainless" nuts and washers at Canadian Tire and similar stores. There are different grades of stainless steel. I used a few locking washers that I bought from Canadian Tire and they corroded very quickly. I subsequently noticed that the Candian Tire washers were more magnetic than more expensive washers that I purchased from Calgary Fasteners (which made sorting out the two types that I had mixed in a box a lot easier). I suspect that the Canadian Tire washers contain a higher proportion of Ni to Cr and are therefore cheaper to manufacture but less resistant to corrosion (and more magnetic).

No problem with using locktite. If your objective is to prevent hanger theft, then locktite helps by making the nuts more difficult to remove. If your objective is to stop hangers loosening up (e.g. where they may be subjected to a strong sideways pull), then you could use locking washers instead.

Hope this helps,

jon jones

P.S. How many stainless nut/washers do you need for your Hilti bolts? I have extras. (Contact me through the Contact TABVAR link).