Steel tubing can be made from various raw materials, like iron, carbon, manganese, vanadium, and zirconium. Like a pipe, tubing can be produced as either seamless or welded. Seamless tubing is a solid block of steel that is rolled into a round shape and then pierced and stretched to its final length.
While Welded steel tubing, on the other hand, is made from the coil. The coil is slit and then rolled up into a round shape, and the ends are welded together. From there, the tubing can simply be cut to a certain length as round tubing.