Simpson Strong-Tie® Strong-Drive structural fasteners are engineered and extensively tested to efficiently meet your most demanding wood and metal applications. The Strong-Drive family is designed to install easier than other fastening methods, which saves time and money. The WSVF Subfloor screw was developed for fastening subfloor sheathing using the Quik Drive® auto-feed screw driving system. It has been re-engineered to reduce driving force and increase installation speed. Strong-Drive® WSVF SUBFLOOR Screw (Collated) — #9 x 3 in. T25, Gray (1000-Qty) (Pack of 100).