Simpson Structural Screws SDWS22400DB-RC12 HT-86B 12Pc 4" Struc 6L Screw Type T-40 Bit required with deep 6-lobe recess to prevent cam-out Low-profile heads allow hardware installation to be virtually flush Head is stamped with Simpson Strong Tie Stamp and fastener length for easy identification Bold thread design provides superior holding power and cInches fastened members together for consistent installation Tan double barrier double coating for exterior applications