What a Universal H Beam Is
A universal H beam is a hot-rolled section with two parallel flanges and a web of the same nominal thickness, forming an H-shaped cross-section. The geometry concentrates steel in the flanges where bending stress is highest, giving an efficient strength-to-weight ratio for columns and beams in building and civil works.
Grades for Industrial and Civil Construction
Q235 (GB/T 700-2006): minimum yield 235 MPa and tensile 370-500 MPa, the economical grade for general frames
Q355 (GB/T 1591-2018): minimum yield 355 MPa and tensile 470-630 MPa, the successor to Q345 for higher-strength structures
Both grades are weldable with standard processes, and the impact class B, C, D or E is selected according to the service temperature of the structure.
Section Series: HW, HM and HN
GB/T 11263-2017 defines three series of hot-rolled H sections. The HW series has wide flanges and suits columns and members loaded in both directions; the HM series is the general-purpose middle series; and the HN series has narrower flanges, optimised for beams under bending. Section depths range from about 100 mm to over 900 mm, with standard lengths of 6, 9 and 12 m.
How Universal Rolling Works
Universal H sections are rolled in a universal mill with four rolls that form the web and both flange faces simultaneously. This produces parallel flanges with accurate dimensions and controlled tolerances, unlike older beam mills that left tapered flanges. The result is a section with consistent geometry that simplifies connection detailing and erection.
Fabrication and Welding
H beams are cut, drilled, coped and welded under qualified procedures to AWS D1.1 or GB 50661. End plates, stiffeners and base plates are shop-welded, and members are delivered marked and certified for site assembly. Cambering can be applied where the design requires pre-camber under load.
Applications
Industrial buildings: portal frames, crane girders and mezzanines
Civil construction: bridges, retaining structures and towers
Commercial buildings: columns and floor beams
Infrastructure: pipe racks, gantries and support structures
Frequently Asked Questions
Q: What is the difference between Q235 and Q355 H beams?
Q355 guarantees a minimum yield of 355 MPa against 235 MPa for Q235, so a Q355 section carries more load at the same size or allows a lighter section.
Q: Is Q345 still supplied?
Q345 has been replaced by Q355 in GB/T 1591-2018; current specifications should use Q355.
Q: Which series should I use for columns?
The HW wide-flange series is preferred for columns because the broad flanges give good stability in both directions.
Q: What lengths are available?
Standard lengths are 6, 9 and 12 m, with cutting to exact length available.
Q: Can H beams be galvanized?
Yes, hot-dip galvanizing to BS EN ISO 1461 is available for outdoor and corrosive environments.
Q: Are mill certificates supplied?
Yes, mill test certificates record the heat number, chemistry and mechanical properties of every beam.