Channel steel is a relatively new economical construction steel. Its section style is economical and applicable, and its mechanical properties are good. Its advantages are shown vividly in the rolled section. Compared with ordinary I-beam, it has the advantages of large section modulus, light weight, metal saving, etc., and can reduce the building structure by 30-40%. Since the inside and outside of the leg are parallel, the leg is right angled and the parts are assembled, which can save 25% of the welding and riveting work. It is commonly used in large buildings (such as factory buildings, high-rise buildings, etc.), supports, root piles, etc.