carburetor screws

[swid]

Is there a reason the screws are made of brass, or can I replace them with steel ones?

And does anyone know what size to use?  It looks like the float bowls and the other side have different sized screws.

[The Buddha]

They are steel, just yellow dyed steel. I swap em for allen head stainless. Steel will rust. Phillips will strip. Allen can be fiddles and removed with it still on the bike.
I have bolts I could sell ya, I have a whole jet pack as well I include bolts in.
Cool.
Buddha.