What is the difference between H-beams and I-beams in steel structures?

Steel structure buildings are made of steel as raw materials, and H-beams and I-beams are two types of large-scale steel members that are often heard. What is the difference between the two? For example, in the following two pictures, which is H-beam and which is I-beam?

Friends who are familiar with steel structure buildings can see at a glance that the first picture is I-beam and the second picture is H-shaped steel. The following editor will introduce the difference between the two.

6 points difference between H-beam and I-beam:

1. From national standards

They all have their own national standards. The national standard for hot-rolled H-beams is (GB / T11263-2005), and the national standard for I-beams is (GB / T706-2008 hot-rolled steel).

2. From the appearance

The flange of the H-shaped steel is flat, and the thickness does not change, while the flange of the I-beam is gradually thinned from the root to the edge, with a certain angle, the inner edge of the flange has a slope of 1:10, which is to distinguish Salient features.

3. From performance

The I-beam section has good straight pressure and tensile strength, but the cross-sectional size is too narrow to resist torsion. H-shaped steel is the opposite, both have advantages and disadvantages.

4. From the product use

I-beams can generally only be used directly on members that are bent in the plane of their webs or form lattice-shaped load-bearing members. It is not suitable for axial compression members or members that are bent perpendicular to the plane of the web Adopted, which makes it very limited in the scope of application, generally used for beams.

Different from the general I-shape, the flange of the H-shaped steel is widened, and the inner and outer surfaces are usually parallel, which can facilitate the connection of high-strength bolts and other components. Its size constitutes a reasonable series, complete models, easy to design and choose (except for I-shaped steel for crane beam), can be used for structural load-bearing columns.

5. From the production process

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

6. From the model

The model of the I-beam is expressed by the Arabic numerals of its waist height in centimeters. If the model has the same waist height, add a, b, c to the back, such as 20a, 20b, 32c, the waist height of the first two is 20cm , And the thickness of the web, flange and flange width are different; and the H-shaped steel is divided according to the width, middle and narrow of the flange, which are expressed by HW, HM, HN and the size of the web and flange, respectively. For example, HM500x300x11x15 means waist height 500mm, thickness 11mm, flange width 300mm, and thickness 18mm. In fact, this is just a theoretical value and will deviate from the actual one.