OVERVIEW: Strong-Drive SD CONNECTOR Screw #9 x 2-1/2 in. 1/4-Hex Drive, Mech. Galv. The Strong-Drive SD Connector screw is specifically designed to replace nails in certain Simpson Strong-Tie connectors and is the only screw approved for that application. The load-rated SD screw has been tested and approved for use in many popular Simpson Strong-Tie products. In certain applications screws are easier and more convenient to install than nails, and the single-fastener load values achieved by the...