I believe they're all 5/16"-18, various lengths.
If you end up having to use carbon steel (SAE5, SAE8,) it is a help to longevity to coat the screw shank, threads, and underside of the head with RTV before it goes in.
This also helps keep the screws from "rusting into place" - so it's win-win (and, RTV acts like a low-grade threadlocker.)