The SDWH timber-hex HDG screw a 0.276 in Dia 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 in and 5/8 in HDG bolt/washer/nut assemblies (two screws for one bolt in many conditions) with the new Strong-Drive SDWH timber-hex HDG screw.