my 2 cents,, (to just hold a screen in place I'd hazard a guess that virtually anything would work, at 2m thick basically any sheet metal screw or self tapping screws. (both work in aluminum) if you want the threaded inserts (for a deeper and proper thread) you can use the 'Keystone' brand inserts and just cinch them with a vise (or even a hammer) no need for special installation tools, and they won't pull out like the pem nuts above.. i use the 6-32 inserts here every week , usually just closing them in a vice.-it's not even worth setting up the installation tool if i'm doing just a few..