Simpson Strong-Tie #12 x 2" Self-Drilling Screw with Wings, Flat Head - 410 Stainless Steel, Qty. 100When you need to fasten wood, plywood or fiber cement board directly to steel framing without pre drilling, this Simpson Strong Tie F12C200FDC Self Drilling Flat Head Screw With Wings delivers the performance you expect. Wings create a clearance hole in the top material so the shank will not ride up, then break off as the drill point engages steel. The flat countersunk head offers a clean, flush finish and the full length machine screw threads provide