Steel pipe manufacturing annular parts, can improve material utilization, simplify the manufacturing process, saving material and machining time, such as bearing rings, jack sets, has been widely used to make steel. Steel or a variety of conventional weapons indispensable material, barrel, barrel would have to make steel. Pipe according to different cross-sectional shapes can be divided into tube and shaped tubes. Because in the perimeter of equal conditions, the largest area of a circle with a circular tube can carry more fluid. In addition, the circular cross section to withstand internal or external radial pressure, the force is uniform, so the vast majority of pipe is pipe. However, the tube also has some limitations, such as under the conditions by plane bending, tube as good as square, rectangular tube large flexural strength, the skeleton of some farm machinery, steel and wood furniture on the popular square, rectangular tube. According to different uses should also have other cross-sectional shape of the shaped pipe, such as square, rectangular, semi-circular, hexagonal, equilateral triangle, octagon and complex section steel - equilateral hexagonal steel pipe, five plum-shaped pipe, steel double convex, double concave steel, oval-shaped steel conical pipe, corrugated steel pipe, steel pipe and other shaped steel case. steel tube according to the production method of classification
(1) seamless steel pipe is a hollow cross-section, no seams around the long bar of steel. Such as hot-rolled, cold drawn tubes, extruded tube, top tube, cold-rolled.
(2) welded steel pipes, also known as welded pipe, steel pipe steel sheet or strip after curl forming welded steel. Welded steel pipe production process is simple, high production efficiency, variety specifications, less capital equipment, but the general strength less than seamless steel tubes.
2, steel tube by use classification - pipes with steel pipes, steel pipe thermal equipment, industrial machinery and steel, petroleum, geological drilling steel, container steel, chemical industry with steel pipes, steel pipes for special purposes.