Seamless pipes are derived from solid steel that is in sheet or bar form and is formed into a solid round shape known as “billets” which are then heated and cast over a form such as a piercing rod to create a hollow tube or shell. These kinds of pipes are known for their ability to withstand pressure more efficiently in comparison to other methods of pipe manufacturing processes, as well as being fast and cost-effective. Seamless pipes are generally used in gas lines, as well as pipes that carry liquids.

Square tube is a name for square tube and rectangular tube, which is usually made of strip steel after processing and rolling. ‌ Specifically, square tube is formed by unpacking, flattening, curling and welding the strip steel into round tube, then rolling the round tube into square or rectangular tube according to the needs, and finally cutting it into specific lengths as needed. ‌