[Richard]

If you want it to hold, then get the next bigger size screw. Bigger diameter, not longer. Yes, the head will protrude slightly, but it you use oval head screws it will look rounded. Remember it is going into aluminum, so don't gorilla tighten it.

Take the screw with you to Lowes, and go to the speciality screw drawers. They have a wide selection of SS oval head sheet metal screws. I filled up one of those little parts sorter trays with #6 through #14 screws in a couple of lengths. Before that I always seemed to need a stainless sheet metal screw somewhere on the coach.