Two Designation Systems, One Structural Function
Hot-rolled beams are traded under two parallel naming systems. The European family covers IPE parallel-flange I beams, UPE parallel-flange channels, and HEA and HEB wide-flange beams, with dimensions and masses tabulated in EN 10365. The Chinese and Japanese families describe comparable shapes through the HW, HM and HN series of GB/T 11263 and the H-section tables of JIS G3192. An IPE 200 and an HW 200x200 are therefore not interchangeable: flange width, web thickness and mass per metre all differ, so substitution must be checked against real section properties rather than nominal depth.
All four European profile types follow the same route: reheating of continuously cast blooms, multi-pass universal rolling, hot sawing, straightening and cold sawing to ordered length. Delivery condition is normally as-rolled, with normalized or thermo-mechanically rolled material specified when low-temperature toughness is required.
Dimensional and Mass Reference
| Profile | h (mm) | b (mm) | tw (mm) | tf (mm) | Mass (kg/m) |
|---|---|---|---|---|---|
| IPE 80 | 80 | 46 | 3.8 | 5.2 | 6.0 |
| IPE 200 | 200 | 100 | 5.6 | 8.5 | 22.4 |
| HEA 200 | 190 | 200 | 6.5 | 10.0 | 42.3 |
| HEB 200 | 200 | 200 | 9.0 | 15.0 | 61.3 |
| UPE 200 | 200 | 80 | 6.0 | 10.5 | 22.8 |
The IPE series runs from IPE 80 up to IPE 750 and the HEA and HEB series extend to 1000 mm depth. Sections deeper than roughly 400 mm are almost always parallel-flanged, and very heavy or very long members are produced as welded built-up sections when the required grade cannot be rolled economically.
Grade Requirements in EN and GB Standards
| Grade | Standard | Min. yield (MPa) | Tensile strength (MPa) |
|---|---|---|---|
| S235JR | EN 10025-2 | 235 | 360-510 |
| S275JR | EN 10025-2 | 275 | 410-560 |
| S355JR | EN 10025-2 | 355 | 470-630 |
| Q235B | GB/T 700-2006 | 235 | 370-500 |
| Q355B | GB/T 1591-2018 | 355 | 470-630 |
| SS400 | JIS G3101 | 245 | 400-510 |
Yield values above apply to the thinnest element group, in most cases 16 mm and below; both EN 10025-2 and GB/T 700-2006 step the requirement down as flange thickness increases. Impact testing is set by the quality suffix: JR at +20 C, J0 at 0 C and J2 at -20 C, each with a minimum absorbed energy of 27 J. Chemistry limits are not identical between systems. EN 10025-2 caps carbon at 0.21 % for S275JR and 0.24 % for S355JR in the 40 mm-and-under range, while GB/T 700-2006 limits Q235B to 0.20 % carbon, 1.40 % manganese, 0.045 % phosphorus and 0.045 % sulphur. Inspection documents are issued to EN 10204 3.1 with heat number traceability.
Tolerances, Marking and Corrosion Protection
Depth, flange width, web eccentricity and out-of-square tolerances follow the section standard EN 10365; fixed lengths are normally cut to 0/+100 mm, and straightness is controlled to about 0.2 % of length. Members carry the grade, heat number and casting number required for execution class EXC2 and above under EN 1090-2. For exposed service, hot-dip galvanizing to ISO 1461 gives a minimum local coating thickness of 70 micrometres on steel 6 mm and thicker, and for corrosivity categories C4 and C5-M a duplex system of galvanizing plus a paint scheme qualified to ISO 12944-5 is the usual specification.
Frequently Asked Questions
Q: Can S355JR beams be substituted directly for Q355B?
A: Mechanically the two grades are close, because both require a minimum yield of 355 MPa and 470-630 MPa tensile at 16 mm and below. They are not the same document, however: GB/T 1591-2018 controls carbon, manganese and microalloying additions in more detail, and each grade is qualified by a different impact class. Any substitution should be approved by the design engineer and recorded on the inspection documents.
Q: What does the JR, J0 or J2 suffix mean on a beam grade?
A: The suffix states the Charpy V-notch impact test temperature: JR at +20 C, J0 at 0 C and J2 at -20 C, all with a 27 J minimum absorbed energy. The choice follows the design service temperature and the governing national rules for brittle fracture, such as EN 1993-1-10.
Q: Are HEA and HEB sections interchangeable at the same nominal depth?
A: No. At a nominal 200 mm depth, HEB 200 is 200 mm deep with a 200 mm flange and a 15 mm flange thickness, giving 61.3 kg/m, while HEA 200 is 190 mm deep with the same flange width but a 10 mm flange thickness, at 42.3 kg/m. HEB delivers more bending capacity at noticeably higher mass.
Q: Is IPE 80 available in lengths over 12 m?
A: Standard stock lengths for small profiles are 6 m and 12 m. Longer single pieces are normally supplied as welded built-up sections, because transport limits and straightness control make long rolled lengths uneconomic.
Q: How should these sections be stored before erection?
A: Stack them on timber bearers at about 2 m centres clear of the ground, keep each stack level to avoid permanent set, and keep galvanized material separated from bare steel to prevent bimetallic contact. Storage in a coastal yard for more than a few weeks usually requires a coating or a temporary protective system.
Q: What data are needed to price a mixed profile order?
A: Profile designation, steel grade with quality class, quantity in pieces or metres, fixed or random length, coating requirement, and certificate type. Any drilling pattern, camber or cutting tolerance outside the standard should be stated separately so it can be priced as an operation rather than as material.