Seamless steel pipe is a kind of long steel with hollow section and no joint around.  The steel pipe has a hollow section and is widely used for conveying fluid pipelines, such as conveying oil, natural gas, gas, water and some solid materials.  Compared with solid steel such as round steel, steel pipe has the same bending and torsional strength and lighter weight. It is a kind of economic cross-section steel and is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipe, automobile drive shaft, bicycle frame and steel scaffolding used in construction.  

Manufacturing ring parts with steel pipe can improve material utilization rate, simplify manufacturing process, save material and processing time, such as rolling bearing ring, jack sleeve, etc., has been widely used to manufacture steel pipe.  Seamless steel pipe or all kinds of conventional weapons indispensable material, gun barrel, barrel and so on to make steel pipe.  Seamless steel pipe can be divided into round pipe and special-shaped pipe according to the shape of cross-sectional area.  Since the area of a circle is maximum with equal perimeters, more fluid can be transported with a circular tube.  In addition, the annular section under internal or external radial pressure, the force is more uniform, so the vast majority of steel tubes are round.