Stainless Steel Torx Pan Head Self Drilling Screws
Star-Drive or 6 Lobe TEK Point Screws in 410 Stainless Steel
Self-drilling screws have a sheet metal thread with a self-driller cutting (TEK) point to pierce through 20 to 14 gauge metals. The higher the TEK number, the larger the drill point to pierce heavier gauge metals.
Torx Pan head self drilling screws are made of 410 stainless steel and have a sheet metal thread with a self driller cutting (TEK) point to pierce through 20 to 14 gauge metals. The heads use a Torx T-10 through T-27 driver depending on the size of the screw. These screws are used in the exterior elements.
Torx 6-Lobe Pan Head Self Drilling Sheet Metal Screws are used because of the unconventional and efficient drive style. The Torx 6 Lobe drive style is designed so that the driver will not slip out of the fastener recess during installation, since the driver is not inherently centered on the fastener. This creates a lesser chance of screw stripping as well as allowing for a higher torque installation. A benefit/disadvantage of non-typical fasteners (depending on your point of view) is that it can be more difficult for users of a device to disassemble it than if more-common head types were used, but Torx and other drivers are widely available. Torx Drive Screws are also known as 6 Lobe, Star Drive and Hexalobular.
Harder than 18-8 stainless but with less corrosion resistance, 410 stainless is commonly used to make roofing screws, siding screws and self tapping (or self drilling) screws, because it is a harder material than the metal being fastened in these types of applications.