Hexagonal Head Self Drilling Screw With EPDM Washer Tianjin Ruiya Internation St Co., Ltd. Base Info Material:Carbon SteelType:Hexagon HeadHead Style:RoundConnection:Common BoltGrade:12.9Trademark:E-starOrigin:China Mainland Description Pre:Fine Thread Gypsum Screw Next:Coarse Thread Drywall Screw Black Color