Simpson Structural Screws SDS25112-R25 1/4-Inch by 1-1/2-Inch with 1-Inch threaded Structural Wood Screw, 25-Pack Strong Drive SDS Structural Wood Screws Designed For Installation In Simpson Strong Tie Connectors As Well As Wood To Wood Applications Low Speed 1/2" Drill With A 3/8" Hex Driver Is The Recommended Tool For Installation 3/8-Inch hex head Patented 4-Cut point and type 17 point enables easy driving without pre-drilling and minimalm splitting Head is stamped with Simpson Strong Tie Stamp and fastener length for easy identification Low speed 1/2-Inch drill with 3/8-Inch hex driver recommended for installation Meets ICC-ES ESR-2236 codes