1、 Square tube is a kind of hollow square section steel square tube, also known as steel cold-formed section. It is made of hot-rolled or cold-rolled steel strip or coil as blank, which is formed by cold bending and then welded by high-frequency welding. Except for wall thickness thickening, the corner size and edge straightness of hot-rolled ultra-thick square tube reach or exceed the level of resistance welding cold-formed square tube
2、 Seamless square tube is a kind of long steel with hollow section and no seams around it. Square tube has hollow section and is widely used as pipeline for conveying fluid. It is mainly used in liquid transportation, hydraulic support, mechanical structure, medium and low pressure, high pressure boiler tube, heat exchange tube, gas, oil and other industries
