In message , alan_m
writes

Use stainless steel screws - anything else (except brass) is likely to
rust over time, especially the screw head. Possibly not too much of a
problem until you want to remove the pan for maintenance purposes

The one I removed a couple of weeks ago was held by four brass screws
only, and had been solid in use, since 1979. The screws came out
easily, and the pan itself then just lifted off the floor. Were I
replacing it, I would, as Alan suggests, run a bead of silicone around
the base.
--
Graeme