Tianjin Rainbow Steel manufactures square tube which is a kind of long strip steel with hollow section and no seam around it. It is a square tube formed by extrusion of seamless tube through four sides of die. Square tube has hollow section and is widely used as a pipe for conveying fluid. It is mainly used in liquid transportation, hydraulic support, mechanical structure, medium and low pressure, high pressure boiler pipe, heat exchange pipe, gas, oil and other industries. It is stronger than welding and not crack.Hot rolled steel tubes are manufactured by passing sheet metal through rollers to achieve specific physical dimensions. The finished product has a rough surface finish with radiused corners, and either a welded or seamless construction. Manufacturing hot rolled square steel tubing involves rolling the steel at temperatures exceeding 1,000 Degree.