Simpson 0.390 x 9-1/2" Strong-Drive SDCF TIMBER-CF ScrewModel No. SDCF27912 Coating Material. Yellow Zinc Coated Length. 9 1 2 Head Diameter (in.) 0. 725 Shank Diameter (in.) 0. 29 Drive Type. T50 6 Lobe Head Type. Flat Head with Nibs Thread Length (in.) 9 1 8 The Strong Drive SDCF Timber CF screw is a structural fastener designed for cross laminated timber construction, mass timber construction and general interior applications. These structural fasteners provide uncompromised strength for these demanding