H-Beam vs I-Beam: Differences, Uses and How to Specify

H-beam and I-beam are often used as if they mean the same thing. In Chinese standards and many export inquiries, they are different products with different shapes, sizes and standards. Ordering the wrong one can affect connections, fabrication and your design check.

This guide explains the differences and how to write each section correctly in an inquiry.

H-Beam vs I-Beam at a Glance

Feature	H-beam	I-beam
Flanges	Parallel inner and outer faces	Tapered inner faces
Flange thickness	Uniform	Thicker near the web
Typical Chinese standard	GB/T 11263	GB/T 706
Typical names	HW, HM, HN series	I20a, I25b and similar
Bolted connections	Flat flange faces simplify connections	Tapered faces may need bevel washers
Common uses	Columns, frames and main beams	Lighter beams, supports and tunnel arches

The Main Difference Is the Flange

An H-beam has flanges with parallel faces and a uniform thickness. An I-beam has flanges that taper, so they are thicker near the web and thinner at the edge. This single difference affects how the section carries load in different directions and how easily you can connect to it.

When to Use an H-Beam

• Columns and frames: wide flange sections have good stiffness about both axes, which helps members under compression.
• Large span and heavy structures: the HW, HM and HN series give designers a wide choice of proportions.
• Bolted and welded connections: parallel flange faces make connections simpler to detail and fabricate.

When to Use an I-Beam

• Beams loaded mainly in one direction: the section works most efficiently about its strong axis.
• Tunnel arches: I-beams are commonly bent to shape for initial support. See our tunnel structure page.
• Existing designs and repairs: keep the original section unless the engineer approves a change.

Can You Substitute One for the Other?

Not automatically. Two sections with the same nominal depth can have different section properties, weight, flange width and connection details. Any change should go back to the structural engineer, who can check strength, stability and connections.

How to Read H-Beam and I-Beam Sizes

• H-beam: HN300×150×6.5×9 gives series, height, flange width, web thickness and flange thickness in millimetres.
• I-beam: I20a gives a nominal height of about 200 mm. The letter separates sections of the same height with different proportions.
• Other markets: names such as W, UB, UC, HEA, HEB and IPE belong to other standards. They are similar in concept but not automatically interchangeable.

What to Include in Your Inquiry

Hot-rolled H-beam, GB/T 11263, HN300×150×6.5×9, Q355B, 12 m, 100 tons, mill test certificate, CIF [destination port].

• Section type, size and standard
• Grade, such as Q235B, Q355B, S355JR or A572 Gr.50
• Length and tonnage by size
• Any cutting, drilling, painting or galvanizing
• Certificate and inspection requirements

Frequently Asked Questions

Is an H-beam stronger than an I-beam?

It depends on the sections compared and how they are loaded. Compare the actual section properties for the same use, not just the shape name.

What does "wide flange beam" mean?

It generally refers to a section with parallel flanges, like an H-beam. Exact sizes depend on the standard, so name the standard in your order.

Can H-beams be welded instead of hot rolled?

Yes. Welded sections are built up from plate and can make sizes outside rolled ranges. Say clearly which type you need.

Get the Right Section

Shanghai Banzhijia Steel supplies H-beam and I-beam for building, stadium, tunnel and industrial projects. Send us your section list, and our sales team will reply with a quote.