Strong-Shield Coated Hex Washer Head Self Drilling ScrewsACQ Compatible & Features Rust/Acid Protection#12-24Hexagon drive for use with a wrench or socketFully Threaded from tip to headIntegral washer at the top of the head to minimize chance of pull-through Washer portion of screw distributes pressure over a larger surface areaTEK 5 Point used for drilling into structural steelStrong-Shield coating features high corrosion resistance and protection from acid rain & rustDesigned to work with ACQ treated lumberExceeds 1,000/hrs. salt spray resistanceThe higher the TEK number the larger the drill point to pierce heavier gauge metals. TEK-5 self drill points are capable of drilling into structural steel. Hex Head Self Drilling Sheet Metal Screws are installed with a socket or hex nut driver. Hex Washer Head Self Drilling Screws are used in the exterior elements and are corrosion resistant due to the Strong Shield coating.