We welded pre-galvanizde steel coil of certain thickness as 0.8mm or 0.9mm or 1.0mm into square section long tubing then cut them incto different short lengths according later usage requirement, as varieties welding location requirement.Dry and shinning the surface with light oil to ensure long-term purpose of anti-rust as long as half year even one year,then swaged the ends of long tubing or expend then other end to ensure they can insert each other tightly,meanwhile for vertical lengths tubing,the whole fabricated process are cut them into short certain length and punch tubing body with certain deepth caulks,besides flatted the two ends of each piece with nipples for easy welding process .Certainly,with long-term experience almost 20 years, we can make finished tubing we called steel frame joint bars not only by sqaure tubing,we can make them by round tubing,it also depends on the requirement from customer and certainly depends on quantity one time need as one time one shipment more than 20 sea feet container,then almost everything can going very well,whenever touch your heart don't hesitate to contact weifang east steel pipe co.,ltd. the right person is Bill with cell number of one three five six two six two four two one two.earlier contact earlier amazing business sucsess.We ask for different payment terms based clients capability and business cooperation period, whenever and whatevery with longer time of business facts, clients would increase their confidence and tu