How the Three Relate
H, W and S beams all use an I-shaped section; the differences come from the standard system and the section detail. H-beam is the general term for I-shaped sections under the Chinese standard system. W (wide flange) and S (standard beam) come from the US system, where the main differences are flange width and whether the inner face of the flange is tapered.
Whatever standard the drawings use, procure and detail to that standard's section series rather than mixing names.
Section Geometry
| Type | Flange | Inner face | Typical use |
|---|---|---|---|
| H-beam | Wider, near-uniform thickness | Parallel | Beams, columns, portal frames |
| W beam | Wide flange | Parallel | Beams and columns; better in biaxial action |
| S beam | Relatively narrow | Tapered | Beams loaded mainly in bending |
Behaviour and Use
The wider and more parallel the flange, the smaller the difference between strong and weak axes, so the member performs better in both directions and suits compression columns or biaxially loaded members. A tapered inner face changes bolt layout, bearing and connection-plate detailing, so the corresponding standard's connection details apply during detailing and fabrication.
Reading Designations
The same section family is designated differently across standards: some use depth and weight, others use depth with flange width. On receiving drawings, confirm the designation system first, then convert it to a procurable size. A letter such as H or W alone does not fix the section.
Selection Advice
- Mainly compression or biaxial loading: prefer wide flanges with parallel inner faces.
- Mainly one-way bending: a narrower flange can work, but check stability and deflection together.
- Complex connections or exposed members: consider joint detailing and appearance early.
What to Send for a Quotation
Provide at once: the standard and designation, grade, quantity and length, cutting and drilling requirements, weld and inspection requirements, surface treatment, and delivery destination. Complete inputs cut a lot of back-and-forth.
Common Questions
Can H-beams and W beams replace each other? Not simply. Their size series differ, so a substitution needs the capacity and connections re-checked.
Does a tapered flange affect fabrication? It changes connection and assembly practice, which detailing must handle to the relevant standard.
To have H-beam members supplied or fabricated to drawing, see custom built-up H-beams and structural steel materials; fabrication scope is on structural steel fabrication. Send drawings and section requirements for review.