Two Ways to Make an H-Shaped Section
An H-shaped section can be produced in two fundamentally different ways. A hot-rolled H-beam is rolled from a heated beam blank in a universal mill, which shapes the web and flanges in one continuous process. A cold-formed or built-up H-section is either bent from strip or, more commonly, welded from three plates, a web and two flanges. The production route changes the applicable standards, the mechanical properties and the tolerances, so buyers need to know which type they are ordering.
Standards for Hot-Rolled H-Beams
Hot-rolled H-beams are governed by a material standard plus a dimensional and tolerance standard:
European practice: material to EN 10025, sections to EN 10024 or EN 10034 with tolerance per EN 10034.
American practice: material to ASTM A992 or A572, with general requirements and tolerances per ASTM A6.
Chinese practice: material to GB/T 1591 or GB/T 700, with dimensions and tolerances per GB/T 11263.
These standards guarantee the section properties because the rolled shape is produced to tabulated dimensions.
Standards for Cold-Formed and Welded H-Sections
Built-up H-sections follow fabrication standards instead of rolling standards. The plates are ordered to EN 10025, ASTM A36 or A572, and the welding and fabrication follow EN 1090-2 in Europe or AWS D1.1 in North America. Cold-formed sections, where strip is bent into an H-like profile, follow EN 1090-1 with design rules from EN 1993-1-3, which accounts for the effects of cold forming. Welding procedure qualification, welder certification and inspection requirements apply to every built-up section.
How the Properties Differ
The two routes produce visibly different steel behavior:
Hot-rolled sections have uniform properties through the section, with residual stresses concentrated in the web, and the mill certificate covers the whole profile.
Welded sections have a heat-affected zone at each weld, so the properties are not uniform, and the weld quality must be verified by inspection.
Cold forming raises the yield strength at the corners through strain hardening, which EN 1993-1-3 allows designers to use, but it also reduces ductility at the bends.
Welded H-sections can use thicker flanges and custom depths that no rolling mill offers, at the cost of welding and inspection.
Choosing Between the Routes
Hot-rolled H-beams are the economical default for standard sizes, giving consistent quality, fast delivery and simple documentation. Built-up welded sections are chosen when the design needs a depth or flange thickness outside the rolled range, when the quantity is too small for a special rolling, or when local fabrication is preferred. The choice is usually settled by comparing the total cost including fabrication, inspection and certification for the project volume.
Frequently Asked Questions
Q: Which standard covers hot-rolled H-beam tolerances?
EN 10034 in Europe, ASTM A6 in North America and GB/T 11263 in China are the main tolerance documents for hot-rolled H-sections.
Q: How are welded H-sections governed?
Built-up H-sections are fabricated to EN 1090-2 or AWS D1.1, with the plate material ordered to EN 10025 or ASTM specifications and welds inspected accordingly.
Q: Are welded H-beams as strong as rolled ones?
They can be made stronger or heavier, but the properties are not uniform because of the heat-affected zones, so the weld quality must be verified and the design accounts for it.
Q: Does cold forming change the steel properties?
Yes, cold forming raises the yield strength at the corners through strain hardening, and design standards such as EN 1993-1-3 allow this effect to be considered.
Q: When should a welded H-section be chosen instead of a rolled beam?
When the required depth, flange thickness or length falls outside the rolled range, or when local fabrication with plate material is more economical for the project.