An H-beam is a steel section whose cross-section has the shape of the letter H: two wide flanges connected by a vertical web. Because of this shape the section has good strength and stiffness in two directions, which is why it is widely used as a column and as a heavily loaded beam in steel structures.
H-section versus I-section
The H-section resembles the I-section, but there is a practical difference:
- H-section (wide-flange, UC) — wide, short flanges; the height and width are roughly equal. This makes the section stiff in both directions and suited to use as a column.
- I-section (UB, IPE) — a narrower, taller cross-section; mainly strong in one direction and therefore suited to use as a beam (loaded in bending).
Designations such as HEA 200 or HEB 300 (or UC sizes) give the type and height in millimetres; some ranges are lighter and others heavier for the same nominal size.
Application
H-beams are used, among other things, for:
- Columns — vertical, compression-loaded members in sheds, buildings and portal frames
- Heavy beams — spans carrying large loads
- Foundation piles — driven into the ground as a steel H-pile
- Sheet pile walls and shoring — as a section or support point
- Crane and frame beams — in industrial and commercial construction
The sections are joined by welding or with bolts through end plates and cleats. In a fire, steel often has to be protected (encasement or coating), because its strength falls at high temperature.
Related terms
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