Cold formed section steel refers to various complex cross-section sections made of cold-rolled strip steel by pressure processing at room temperature. Also known as thin-walled section steel, it is a kind of light building structural steel. Cold formed section steel is a kind of economical light-weight thin-walled steel with cross-section, also known as steel cold-formed profile or cold-formed profile. Cold formed section steel is the main material for making light steel structure. It has various extremely thin, reasonable and complex sections that cannot be produced by hot rolling. Compared with hot-rolled section steel, under the same section area, the radius of gyration can be increased by 50% ~ 60%, and the section moment of inertia can be increased by 0.5 ~ 3.0 times, so the material strength can be used reasonably; Compared with ordinary steel structure (i.e. steel structure made of traditional I-beam, channel steel, angle steel and steel plate), steel can be saved by about 30% ~ 50%. In some cases, the steel consumption of cold-formed steel structure is equivalent to that of reinforced concrete structure under the same conditions. It is an economic section steel.

There are many kinds of cold-formed steel sections, including open, semi closed and closed sections. The main products are cold-formed channel steel, angle steel, Z-shaped steel, cold-formed corrugated steel plate, square pipe, rectangular pipe, electric welding special-shaped steel pipe, rolling shutter door, etc. The thickness of cold-formed section steel usually produced is less than 6mm and the width is less than 500mm. There are more than 400 specifications and varieties commonly used in China, such as equilateral angle steel (limb length 25 ~ 75mm), inner crimping angle steel (limb length 40 ~ 75mm), channel steel (height 25 ~ 250mm), inner crimping channel steel (height 60 ~ 250mm), crimping Z-section steel (height 100 ~ 180mm). Products are widely used in mining, construction, agricultural machinery, transportation, bridges, petrochemical, light industry, electronics and other industries.

Cold formed steel is also widely used. It is generally used to make structural parts and auxiliary parts in production departments such as construction, railway vehicles, automobiles and ships.