galvanized square steel tubes Material:Q195 Q235 St52 10# 20# Standard:BS ... Cert:CE,BV,SGS,API Bright,Oiled, galvanized square steel tubes Specification:1. Outer diameter:15*15-400*400mm2.Wall ... appliable.Processing technic:1.Process method:cold drawn, high frequency welded.2.Polishing:600#,400#, 320#, 240#, 180#.etc. ... 86-0315-2247360Fax: 86-0315-2247325Skype:amandawang08 galvanized square steel tubes