Stainless steel
These Steeltite Self Drilling Screws are designed specifically for drilling through thin sheet metal. They feature a drill point end.
Steeltite screws have a Hex flange head and are commonly used as a roofing screw, these are without a neoprene sealing washer.
10 gauge diameter = 4.9mm Thread = 16 TPI Hexagon head size = 5/16"