Hex Washer Head Self Drillers
Self Tapping Hex Head Screws
Hex washer head 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. The heads use a hex nut driver 1/4, 5/16 or 3/8 depending on the size of the screw. These screws are used in the exterior elements.
410 Stainless Steel
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.
Zinc Plated Steel
Zinc plated steel is very common in the fastener industry. Zinc adds a layer of corrosion resistance to plain alloy steel. Clear zinc has a light, shiny color and blue zinc has a bright blue hue. Zinc plated steel is not suitable for extreme environment use, as it is not as resistant to corrosion as hot dipped galvanized.