Unique 4-corner thread form with raised ridge reduces driving torque penetrating the hardest wood products 6-lobe drive virtually eliminates driver bit cam-out Penetrate hardest wood products with ease, often without pre-drilling Made of solid 316 stainless steel for maximum corrosion resistance Threaded approximately 2/3 up shank to tightly draw deck board to joist NOTE: Contractor"s Packs containing 1750 screws will fasten 500 square feet of decking Deck Packs containing 350 screws will fasten 100 square feet of decking (6 boards on 16 centers) 6-Lobe Driver Bit included in both Contractor and Deck Packs Drive flush with surface of workpiece. Gauge x Lgth In=7 x 1-5/8