Simpson Strong-Tie Strong-Drive No. 2 x 8 in. L Star Hex Washer Head Galvanized Steel Structural ScrewsThe SDWH Timber Hex HDG screw a 0. 276 inch diameter hot dip galvanized screw suitable for heavy duty marine and coastal applications. The SDWH Timber Hex HDG screw has a SawTooth point and oversized integral washer that makes for fast installations no predrilling or separate washer needed. Speed up your next pile job by replacing 3 4 inch and 5 8 inch HDG bolt washer nut assemblies (two screws for one bolt in many conditions) with the new Strong