Seamless square tube is a long steel strip with a hollow cross-section and no seams around the periphery. The tube is hollow and has a certain cross-sectional area. Circular tubes have certain limitations, such as lower bending strength than square and rectangular tubes under flat bending conditions. Some agricultural machinery skeletons, steel and wood furniture, etc. commonly use square and rectangular tubes.

Square rectangular pipe is a term for square and rectangular pipes, which refers to steel pipes with equal or unequal side lengths. It is rolled from strip steel through process processing. Generally, the strip steel is unpacked, flattened, curled, and welded into circular tubes, which are then rolled into square tubes and cut to the required length.