H-Beam vs I-Beam: What's the Difference and Which Do You Need?

Buyers often use the two names interchangeably, but the sections behave differently in structures. Here is a practical comparison — and how to read the Chinese HW/HM/HN designations you will see on quotes.

Geometry: the real difference

An H-beam has parallel flanges of constant thickness and a web that meets the flanges at a clean right angle — the profile looks like a block letter H. Traditional I-beams (like the Chinese standard I-shapes or American S-shapes) have tapered flanges — thicker at the web, thinner at the edge. Parallel flanges make H-beams easier to connect: bolted end plates and flange plates sit flat without wedging.

Section efficiency

For the same weight, H-beams generally give a larger section modulus — more bending capacity per kilogram. That is why modern steel structures default to H-sections, while rolled I-shapes survive mostly in older standards and crane rail applications.

Reading Chinese designations

Chinese H-beams come in three series (GB/T 11263):

• HW — wide flange (height ≈ flange width, e.g. HW200×200): columns and compression members.
• HM — medium flange (e.g. HM244×175): general beams and columns.
• HN — narrow flange (e.g. HN250×125): beams, purlins, edge members.

A designation like HW200×200×8×12 means height 200, flange width 200, web 8 mm, flange 12 mm — theoretical weight 50.5 kg/m. European buyers can map roughly: HEA/HB ≈ HW series, IPE-like proportions ≈ HN. Exact equivalence depends on section properties, so send us the required section modulus and we will verify the nearest Chinese section.

When I-beams still make sense

Tapered-flange I-sections remain common where the standard is old (railways, crane rails on I-section) or where existing structures must be extended with matching sections. For new-build structures, columns and mezzanine floors, H-beam is almost always the better buy.

Getting H-beams from Foshan

Our H-beam product page lists the common HW/HM/HN sizes with theoretical weights, in Q235B or Q355B, 12 m stock lengths. We saw-cut to your cutting list, drill bolt holes, and pack by section for export. For combined orders with channel steel and plate, one container carries the whole package.