black welded square steel tube Material:Q195 Q235 St52 10# 20# ... ASTM DIN Cert:CE,BV,SGS,API Bright,Oiled, black welded square steel tube Specification:1. Outer diameter:15*15- ... #, 320#, 240#, 180#.etc.3.Surface Finish:Blank,Black,Bright and Galvanized,and any other special dimensions are availablePacking ... AmandaTel: 86-0315-2247360Fax: 86-0315-2247325Skype:amandawang08 black welded square steel tube