Simpson Collated #9 x 2-1/2" T-25 WSV SUBFLOOR Screw, Yellow-Zinc 750-PkModel No.. HCKWSV212S Coating Material. Yellow Zinc Coated Screw Size. #9 Length (in.) 2 1 2 Head Diameter (in.) 0. 333 Drive Type. T25 6 Lobe Head Type. Rimmed Flat Head with Nibs Shank Type. 2 3 Threaded Shank Thread Type. Variable Thread Design Point Type. High Low Threaded Point Compatible Tools. Quik Drive PRO250G2, PRO300S Packaging Qty. 1000 Simpson Strong Tie has re engineered its popular subfloor screw to reduce driving force and increase