Seamless steel pipe is a kind of round, square and rectangular steel with hollow section and no joints around Seamless steel pipe is made of steel ingot or solid tube blank through perforation, and then hot rolled, cold rolled or cold drawn Seamless steel pipe has a central control section and is widely used as a pipeline for conveying fluid. Compared with solid steel such as round steel, the steel pipe has the same bending and torsional strength and is lighter. It is an economic section steel. It is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipe, automobile transmission shaft, bicycle frame and steel used in construction