Simpson Strong-Tie® has re-engineered its popular subfloor screw to reduce driving force and increase installation speed. Designed for subfloor and sheathing projects, the new Strong-Drive WSV Subfloor screw has been developed for fastening subfloor sheathing using the Quik Drive auto-feed screw driving system. Redesigned tip and thread pattern provide easy starts and up to 25% less torque while driving - makes for up to 20% faster driving. Less installation torque also means less wear on tools. Deep six-lobe recessed ribbed head provides clean countersinking and more secure bit retention for fewer cam-outs. The holding power of WSV screws reduces the gaps between the joist and subfloor that cause floor squeaks. WSV screws can be easily backed out allowing for future access to floor cavities. The box contains 21500 units divide in 50 strips of 30 screws.