Simpson Structural Screws SD9212R100 HT-30B 100Pc #9X2-1/2 Sd Screw 1/4-Inch Hex Head drive reduces cam-out for easier installation Shank is specifically designed to match the fastener holes in Simpson Strong-Tie connectors Optimized heat treated for strength Mechanically-galvanized coating meets ASTM B695 class 55 Connectors installed with SD screw code listed under ICC-ES ESR-3096