... wall thickness +/-0.05mm:d)The mass deviation on a single tube shall not exceed -7.5% of the specified mass ... , gas,…etc.:b)Fabrication of steel manufacture, Greenhouse, Scaffolding tube, Furniture making,Fencing.PLACE OF ORIGINCHINA,TIANJINTARGET MARKETBrazil ,Malaysia, America ... field of black pipe(carbon steel welded pipe)& white tube(galvanized steel pipe)-Tianjin Rongxin Steel Co.,ltd.,locating ...