... -20mm 2.OD:15*15mm-600*600mm 3.Gal shs,rhs,chs 4.Build structure etc. galvanized hollow section CHS,SHS ... ,RHS,GAL.Tianjin Haiyunda Metal Material Co.,Ltd.Rectangular hollow section/ ... ,figure-8 etc.),Tyre chain and so on. CHS SHS RHS Galvanized