I-steel, also known as steel beam, is a long strip of steel with an I-shaped section, and its specifications are expressed in millimeters of waist height H* leg width B* waist thickness D. For example, "work 150*88*6", that is, the waist height is 150mm, the leg width is 88mm, and the waist thickness is 6mm. The specifications can also be indicated by the model, which indicates the number of centimeters of waist height, such as 14#, I-beams with the same waist height, if there is a concentration of different leg height and waist thickness, it is necessary to add abc on the right side of the model to distinguish. Such as 32a#/32n#/32d#, I-steel is widely used in various building structures, Bridges, vehicles, machinery and supports.