Simpson Strong-Tie F12C250FDB Self-Drilling Flat-Head Screw with Wings, #12 x 2-1/2-in. #3 Square Type 410, 1800-Pack

Simpson Strong-Tie F12C250FDB Self-Drilling Flat-Head Screw with Wings, #12 x 2-1/2-in. #3 Square Type 410, 1800-PackFlat countersunk head with self countersinking nibs Machine screw thread, threaded full length Shank slot enhances thread formation in steel and removes exhaust Wings above drill point provide clearance hole in work piece so it won't climb up the shank; wings break off as point engages the steel substrate Compatible driver bit: #2 square drive (model BIT3S 2 R2) 2 1 2 in. length for 2x wood Type 410 stainless steel is coated for additional corrosion