SIMPSON STRONG-TIE MTH114S - Quik Drive #7 x 1-1/4", #2 Square, Hi-Lo Thread, Trim Head w/nibs-2500bxExcellent for fastening underlayment to wood, the MTH Wood Screw from Simpson Strong Tie makes smoother work of underlayment to subfloor installations. This particular screw (Item #MTH114S) is sized #7 x 1 1 4", with a #2 square drive. The screw features high low threads and a trim head with nibs. This unique threading prevents squeaks and pullouts, while the trim head allows for a flush surface. MTH underlayment screw are compatible with the Quik