HW is that the height of H-beam and the width of the flange are basically equal; it is mainly used for steel core columns in reinforced concrete frame structure columns, also known as rigid steel columns; it is mainly used for columns in steel structures.

HM is the ratio of H-beam height to flange width is roughly 1.33~1.75, mainly in steel structures: used as steel frame columns, used as frame beams in frame structures bearing dynamic loads; for example: equipment platforms

HN is the ratio of H-beam height and flange width greater than or equal to 2, mainly used for beams; the use of I-beam is equivalent to HN-beam;

1. Whether the I-beam is ordinary or light, because the section size is relatively high and narrow, the moment of inertia of the two main sleeves in the section is quite different. Therefore, it can generally only be directly used in its web. A member that is bent in a plane or is composed of a lattice-type stress member. It is not suitable for axial compression members or members that are perpendicular to the plane of the web and bending, which makes it very limited in the scope of application.

2. H-beams are high-efficiency and economical cutting profiles (others include cold-formed thin-walled steels, profiled steel plates, etc.). Due to the reasonable cross-sectional shape, they can make the steel more effective and improve the cutting capacity. Different from the ordinary I-shaped, the flange of the H-beam is widened, and the inner and outer surfaces are usually parallel, which can facilitate the connection of high-strength screws and other components. Its size constitutes a reasonable series, and the model is complete, which is convenient for design and selection.

3. The flanges of H-beams are of equal thickness, with rolled sections and combined sections composed of three welded plates. The I-beams are all rolled sections. Due to the poor production process, the inner edge of the flange has a 1:10 slope. The rolling of H-beam is different from that of ordinary I-beam, which only uses one set of horizontal rolls. Because its flange is wide and has no slope (or small slope), it is necessary to add a set of vertical rolls for rolling at the same time. , its rolling process and equipment are more complicated than ordinary rolling mills. The maximum height of rolled H-beam that can be produced in China is 800mm, which exceeds the only welded composite section.

my country's national standard for hot-rolled H-beams (GB/T11263-1998) divides h-beams into three categories: narrow flanges, wide flanges and steel piles, whose codes are HZ, HK and HU respectively. Narrow-flange H-beams are suitable for beams or compression-bending members, while wide-flange H-beams and H-beam piles are suitable for axial compression members or compression-bending members. Compared with H-beam, I-beam W, IX and IY are not as good as H-beam under the premise of equal weight.