I use stainless steel studs and brass or stainless dome nuts with fibre washers. The studs must be the right length to allow the nuts to tighten on the washers properly. Use a bit of pipe jointing on the washers if you want; fibre washers are not what they used to be, not much 'squash' in them these days!

Location: Near Cambridge

Robert, I soak fibre washers in warm water before use. Makes them nice and squashy and makes a better joint in my experience

Location: Farnham