Simpson Structural Screws SD10212R500 No.10 by 2-1/2-Inch Stuctural-Connector Screw, 500-Pack 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