30 9 月, 2026
H Beam vs I Beam: Differences, Uses and How to Specify
The difference is in the flange width and the parallelism of the flanges. An I beam has relatively narrow, tapered flanges; an H beam (wide-flange section) has wider, parallel flanges. That makes an H beam more efficient in bending about its strong axis and easier to bolt, which is why it dominates modern structural work.
How the shapes compare
| I beam | H beam (wide flange) | |
|---|---|---|
| Flange | Narrower, with a taper | Wider, with parallel faces |
| Section efficiency | Lower bending efficiency for a given weight | Higher bending efficiency; more of the steel is in the flanges |
| Bolting and connections | Less convenient, tapered faces | Easier, parallel faces give a flat bearing surface |
| Typical use | Legacy structures, monorails, lighter framing | Modern frames, columns, beams, long spans |
| Dimensional standards | Hot-rolled section standards (e.g. GB/T 706 for I beams) | Wide-flange section standards, which are a separate table |
Why the two must not be mixed up
The dimensional tables for I beams and for H beams are different standards. A size that looks close, such as an I beam 200 mm deep and an H beam 200 mm deep, has different flange widths, thicknesses and section properties. Substituting one for the other changes the design, so quote the shape the drawing names and confirm the section properties.
How to specify the right beam
- Use the section designation from the drawing, with its standard
- State the grade, for example a Q235B or Q355B structural grade
- Give the length, the end preparation and the quantity
- If you are substituting, check the section properties rather than the nominal depth
Related reading
Frequently asked questions
What is the difference between an H beam and an I beam?
An I beam has narrower, tapered flanges; an H beam has wider, parallel flanges. The H beam is more efficient in bending and easier to connect, which is why it is the default for modern structures.
Can an I beam be replaced by an H beam of the same depth?
Not automatically. The flange width, flange thickness and section properties differ, and the two come from different dimensional standards, so the substitution must be checked against the design.
Which is stronger, H beam or I beam?
For the same weight, a wide-flange H beam is usually more efficient in bending because more of its steel sits in the flanges. Strength also depends on the grade and the span, so check the actual section properties.
Tell us the standard, grade, form and size you need and we will quote against it. See our steel product catalogue, how we inspect and certify each order, or request a quotation.