... 3)Application:Structure 4)Certification:ISO9001:2000 Hot-dip Galvanized steel pipe 1)Thickness:2.77-6.02mm 2)OD:21 ... Certification:ISO9001:20001)Product Name:ASTM A53 Hot-dip Galvanized steel pipe2)Place of Origin:Nantong China(Mainland)3)OD(mm ... projects; building, central air-conditioning pipe, fence, threading pipe, rolling doors, metal frame, support tube, furniture, sports equipment, fence, etc.13 ...