1. I-shaped steel, whether general or lightweight, can only be used immediately for prefabricated components bent or formed to support prefabricated components in the beam end plan view due to its high and narrow cross-sectional specifications, and the large distance between the inertia moments of the two main sleeves of the cross-section. The selection of prefabricated components subjected to pivot force and curved prefabricated components in the plan view of the vertical split beam end is not suitable, therefore it has great limitations in its application range.
2. H channel steel belongs to aluminum profiles with high efficiency and economic development (including cold drawn thick walled channel steel, profiled plates, etc.), Because the cross-section is effective, it can fully utilize the efficiency of stainless steel plates and improve their cutting capacity. Unlike ordinary I-beams, the flange of H-channel steel is enlarged and the inner and outer surfaces are generally parallel, which is conducive to the connection between high-strength bolts and other prefabricated components. Its specifications constitute an effective series of products, with complete models and specifications, which is conducive to the adoption of design solutions.
The flanges of H channel steel are all of equal thickness, with cold rolled sections, and are also welded from three plates by electric welding. I-beams are all cold-rolled sections. Due to poor production process, there is a 1:10 inclination on the inner side of the flange. The cold rolling of H-channel steel is different from ordinary I-shaped steel, using only one set of horizontal rollers. Due to the wide flange and no inclination (or small inclination), it is necessary to add a set of column rollers for rolling. Therefore, its cold rolling process and mechanical equipment are more complex than ordinary extrusion machines. The height to width ratio of the large cold-rolled H-channel steel that can be produced in China is 800 millimeters, surpassing that only electric welding can form a cross-section.