Simpson Strong-Tie® Collated Screw, series: Strong-Drive® PPSD, Imperial, #8-18 Thread, 1-15/16 in Overall Length, Flat Head, Square Drive, UNF Thread, Pilot Point, #2 Point, #3 Drive, 0.315 in Head, Metal, Quik-Guard® Coated. Simpson Strong-Tie® PPSDQ11516S0818 Strong-Drive® PPSD Collated Screw, #8-18, 1-15/16 in OAL, Flat Head, Square Drive, Pilot Point