Square tube, also known as square rectangular tube, is a name for square tube. Square tubes are divided into seamless and welded seams. Seamless square tubes are made by extruding seamless round tubes. Common square pipes are welded or non-welded. Square tubes are rolled from steel strips through a process. Generally, the strips are unpacked, flattened, curled, and welded to form round tubes. The round tubes are then rolled into square tubes and then cut to the required length.