Galvanic Corrosion

Fasteners for Aluminum

• This article says that stainless is best for screwing in aluminum, but must minimize corrosion such as rubber washer between screw head and aluminum sheet. It does not talk about contact between threads of screw and the aluminum - it appears the head is more important than the threads. [1]
• Stainless and galvanized are ok with aluminum, as long as not salty environment [2]

Deck Screws

• Are deck screws compatible with aluminum?

Aluminum and Galvanized Steel

• Not compatible. Use rubber washer between.

Shopping

• Galvanized pole barn screws for aluminum [3]