H- beam profiles belong efficient and economical cutting surface (there are other cold-formed thin-walled steel, pressure plate, etc.), due to the reasonable cross-sectional shape, they can make steel more play performance, increase the carrying capacity. Unlike ordinary workers are h-shaped steel flanges were widened, and inner and outer surfaces generally parallel, so that makes it easy to connect with high strength bolts and other components. Constitute reasonable sized series, model range, ease of design choice.