Seamless steel tubes are widely used. Seamless steel pipe for general use is rolled by common carbon structural steel, low alloy structural steel or alloy structural steel, with the largest output. It is mainly used as pipeline or structural parts for conveying fluids.
According to different uses, seamless steel pipes can be supplied in three categories: A. according to chemical composition and mechanical properties; B. according to mechanical properties; C. according to hydraulic test. Steel pipes supplied by class A and B should also be subjected to hydraulic pressure tests if they are used for liquid pressure.
Seamless tubes for special purposes include seamless tubes for boilers, chemical and electric power, seamless tubes for geology and seamless tubes for petroleum, etc.
Seamless steel pipe has hollow section, which is widely used as pipeline for conveying fluids, such as oil, natural gas, gas, water and some solid materials. Compared with solid steel such as round steel, steel pipe has lighter weight when their bending and torsional strength are the same, so it is an economic section steel.
In addition, steel pipes are widely used in manufacturing structural and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames and steel scaffolding used in construction, which can improve material utilization, simplify manufacturing process, save material and processing time. Steel pipes have been widely used in manufacturing.