[Flieger]

Originally Posted by Outback Porsche

Hey Max, how's your metallurgy theory?

I'm trying to find out what coating on mild steel fasteners (machine screws) would have the best compatibility with Al 5083-H321 alloy, to limit galvanic corrosion. Any ideas?

Anyone can chime in if they know the answer

I would say zinc since that is also one of the primary alloying elements for aluminum. 7075 uses zinc and has one of the highest yield strengths of any aluminum alloy (excluding scandium-aluminum and other exotic alloys) while having better stress corrosion cracking resistance than the next strongest, 2024 (aka Duralumin).