posted 8 years ago
Drywall screws won't last long in the elements, look for something made for outdoors, coated or plated.
Look for self drilling screws. They have an auger type nose that will drill through light metal but they're a bit pricey. If the metal is thick it could dull the point before breaking through. Self tapping screws are hardened and the threads will cut into metal. Cheaper but you will need to drill a pilot hole to get the point started.