Seamless steel pipe is a hollow section, the surrounding no seam of the round, square, rectangular steel. Seamless steel pipe is made of steel ingot or solid tube through the perforated tube, and then made by hot rolling, cold or cold. Seamless steel pipe with hollow section, a large number of pipes used for conveying fluid, steel and round steel and other solid steel compared to the same flexural strength, the weight is light, is an economic section of steel, widely used in manufacturing structure Parts and mechanical parts, such as oil drill pipe, car drive shaft, bicycle frame and steel scaffold for construction.