Any open at both ends and having a hollow cross section, and a relatively large cross-section of steel whose length and perimeter, can be called steel pipe. When comparing hour length and cross section perimeter, may be referred to the pipe section or tubular parts, they all belong to the category of pipe products.
Steel pipe is an economic cross-section steel, the steel industry is an important product, typically accounts for about 8% -16% of the total amount of steel, which is the range of application in the national economy is extremely broad. Because the tube has a hollow cross-section, and thus most suitable for liquids, gases and solids pipelines; at the same time round compared with the same weight, section modulus of steel, large bending torsional strength, it has also become a variety of mechanical and architectural structures important material. With structures and components made of steel, in case of equal weight, the ratio of the solid component has a greater section modulus. Therefore, metal pipe itself is a saving of economic section steel, it is an important part of efficient steel, especially in oil drilling, refining and transportation and other industries in greater demand, followed by geological drilling, chemical industry, construction industry, machinery industry aspect, aircraft and automobile manufacturing and boilers, medical equipment, furniture and bicycle manufacturing, also requires a lot of various steel pipes. In recent years, with the development of atomic energy, rockets, missiles and aerospace industry, and other new technologies, pipe position in the defense industry, science and technology and economic development even more important.