The Hillman Self-Piercing Sheeter Screws are metal roofing screws engineered to fasten thin pieces of metal to wood, fiberglass or metal primarily through a pre-drilled, or own generated hole in light gauge metal. These sheet metal roofing screws are perfect for roofing construction, and the featured neoprene washer provides a water-tight seal, and prevents corrosion between surfaces. These self-drilling sheet metal screws have a ceramic finish that exceeds the 1000 hour salt spray test, and is recommended for use for treated lumber. No need to pre-drill hole in thin metal Steel-backed neoprene washer for water proofing Ceramic coat provides superior rust and corrosion protection Metal roofing screws recommended for use for treated woods Sheet metal roofing screws measure #10 diameter x 1" length Self piercing screws penetrate metal and tap their own mating threads Self-drilling sheet metal screws in gray hue to match metal sheeting