You see a lot of them in your home—under your bed, above the windows, along the stairway, and even around some of your furniture. Tubes play an important role in your home’s aesthetics and functionality. But have you ever wondered how such useful structural and decorative elements are made? Here’s a glimpse of the tube manufacturing process.
A thick metal plate is cut into strips with width that’s a little shorter than the desired diameter for the tube. The strips go through quality checks and prepared for rolling. Once fed into the rollers, their thickness are reduced, consequently increasing their width. Once the desired width is achieved, the edges are cut and prepared for welding.
Welding the Edges
The welding process depends greatly on the desired shape of the tube. To create a round tube, a metal strip is bent until both edges meet and a perfect circle is formed. If it’s square brass tubing, the strip has to be folded three times until four sides of equal length are formed. Then the open edges are welded to close the structure.
During rolling and welding, stresses caused by voids and unbalanced concentration of material may occur within the tube. These stresses can significantly reduce the strength and durability of the tube, putting them at risk of premature breakage. To remove these stresses, the newly welded tubes are subjected to extreme heat. High temperature will cause the molecules of the metal strips to loosen up and fall into their correct places.
Cleaning and Straightening
Heat treatment can leave traces of scales on the surface of the tubes. These scales and other impurities are carefully removed to ensure that the surface of the tubes are ready for cold drawing and finishing. The process of removing scales is called pickling. The tubes are then stretched and straightened to the designed length.
In most cases, the size of the produced tubes is slightly bigger than the desired size. Cold drawing may be necessary to correct their size. This method works by drawing the tube into a die with a smaller diameter. The tube that comes out of the other end of the die is expected to have the desired size and a smooth surface as well.
Most metal manufacturers and suppliers employ the same method. However, not all of them are using quality machines and have skilled workers. If you need tubes for your project, make sure that you’ll get them from a trusted supplier, such as Rotax Metals.