In use, it is required to have better welding, riveting and comprehensive mechanical properties. Raw steel billets are carbon bound steel or low alloy steel billets with carbon content not exceeding 0.25%. Its specifications are expressed in millimeters of waist height (h)* leg width (b)* waist thickness (d), such as 100*48*5.3, indicating that the waist height is 100 mm, the leg width is 48 mm, and the waist thickness is 5.3 mm, or 10# channel steel. Channel steel with the same waist height, if there are several different leg width and waist thickness, it is also necessary to add a b c to the right side of the model to distinguish, such as 25#a 25#b 25#c and so on. 

 At the same height, light channel steel has narrower legs, thinner waist and lighter weight than ordinary channel steel. No. 18-40 is a large channel steel, and No. 5-16 is a medium channel steel. The imported channel steel shall be marked with actual specifications, dimensions and relevant standards. The import and export orders of channel steel are generally based on the specifications required in use after determining the corresponding carbon bonded steel (or low alloy steel) steel number. In addition to the specification number, channel steel has no specific composition and performance series.