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Parallel Flange Hot-Rolled H-Beam and I-Beam in High-Strength Steel for Steel Frame Buildings
| MOQ: | 1 PCS/20 Tons |
| Price: | $1300-3000 |
| Standard Packaging: | Customized based on project |
| Delivery Period: | 30-60 Days |
| Payment Method: | L/C,D/A,T/T,D/P |
| Supply Capacity: | 15,000 t / month |
High-Strength Parallel Flange H-Beam
,Hot-Rolled Parallel Flange H-Beam
,Parallel Flange Hot-Rolled I-Beam
Two H-beams can both be 300 mm deep and differ by a factor of four in bending capacity. The height is not what decides it — the family the section belongs to, and the way its designation is written, decide it. This guide covers the three naming systems an export buyer is most likely to meet, and where substitution does and does not work.
An H-beam has parallel flanges: the inner and outer faces are flat and square to the web. An I-beam, in the older sense of the word, has tapered flanges — the inner face slopes inwards at roughly 8 to 14 degrees.
The geometry decides how the member is used. A parallel flange takes a bolted end plate, a welded stiffener or a seated connection directly. A tapered flange needs a tapered washer or a welded flat plate before anything can sit on it — which is why I-sections survive in legacy drawings and in crane rails, and rarely in new frames.
In daily speech, "I-beam" is used for both. If the drawing says IPN, it is tapered; if it says IPE or HEB, it is parallel. Check that first.
A hot-rolled H-beam comes off the mill in one piece, with the same metallurgy through the flange and the web, and a rolled surface finish. Its sizes are fixed by the standard, and the mill order decides the lead time.
A welded section is built from plates: web to flange, full penetration, then straightened. It can be any size the plate mill can supply, and it is the normal route for heavy sections and for sizes outside the standard series. What it costs you is a weld and a heat-affected zone in the most highly stressed part of the member, plus the inspection that goes with it.
For a frame in the standard range, hot-rolled is cheaper per tonne and better in fatigue. For a one-off heavy member, welded is the only answer.
The three systems look similar and mean different things. The most common mistake is to read an American designation as a metric one.
| System | Format | Examples | Key Point |
|---|---|---|---|
| GB/T 11263 (China) | Series + height × width (mm) | HW 300×300, HM 294×200, HN 400×200 | HW has a flange at least as wide as the section is deep; HN has a flange roughly half the depth; HM sits between. The series tells you what the section is for before you read a single dimension. |
| EN 10025 / EN 10034 (Europe) | Family + nominal size | HEB 300, IPE 300, HEA 200, IPN 200 | HEA, HEB and HEC are wide-flange sections in light, standard and heavy weights for the same depth; IPE is a parallel-flange I-section; IPN is the tapered-flange version. |
| ASTM A6 (US) | Nominal depth (in) × weight (lb/ft) | W36×350 | W36×350 is 36 inches deep and weighs 350 lb/ft. The second number is not the flange width — that is the single most common misreading in a quotation request. |
Height is the worst possible basis for a substitution. Two sections with the same depth can carry very different moments, because the flange thickness and the web thickness are what fill the section out.
- Q355B and S355JR share a nominal yield of 355 MPa and both are impact-tested at 20 °C. They are close enough for many designs, but they are certified under different standards, with different tolerance and sampling rules. A substitution needs the engineer's signature, not the buyer's.
- HW 300×300 and HEB 300 occupy the same envelope and are not the same member. The flange and web thicknesses differ, so the mass and the section modulus differ. Match on properties, not on the name.
- HN and IPE are both narrow-flange parallel sections but from different series. Check height, width, and both thicknesses against the drawing before quoting.
Three numbers decide whether a beam works: the second moment of area (I), the section modulus (W) and the mass per metre. The first two come from the section table; the third you can check yourself.
Mass per metre in kg/m equals the cross-sectional area in mm² multiplied by 7.85 and divided by 1,000. If a supplier quotes a weight that does not match the area, the section is not what the drawing asked for.
Bending moment rises with the square of the span and deflection with the fourth power, so a beam that is adequate at 6 m is rarely adequate at 9 m. Depth helps far more than flange width does for bending, and far less for lateral stability.
GB/T 11263, EN 10034 and ASTM A6 all specify dimensional tolerance, and they do not agree. Height, flange width, out-of-square, camber and mass tolerance all differ, and so does the inspection routine behind them.
Write the standard on the order, not only the grade. A section that meets GB/T 11263 is not automatically acceptable under EN 10034, and the argument usually happens after the steel has arrived.
- Section: the full designation, plus the standard it is measured against.
- Grade and impact requirement: Q355B, S355JR, S355J2, with the test temperature.
- Length and cut tolerance.
- Surface: mill finish, shot blasted and primed, or galvanized.
- Certificate: EN 10204 3.1 for a structural member.
- Packing and marking, if the site needs to identify bundles.
Not by definition. A parallel-flange H-section usually has a higher section modulus for the same mass, because the flange area sits further from the neutral axis. But a specific I-section can outperform a specific H-section — compare the section tables, not the shape name.
350 pounds per foot — the weight, not the width. The first number, 36, is the nominal depth in inches. The actual depth and the flange width are listed in the ASTM A6 tables.
Often yes in practice, but not automatically. The nominal yield and the 20 °C impact requirement are comparable; the certification route and the dimensional tolerance are not. The substitution needs to be approved against the design standard the project is built to.
The flange width relative to the depth. HW is wide-flange, used for columns and for members where stability governs. HN is narrow-flange, used for beams where bending governs. HM is the middle series, and the one most often used for general frame members.
Hot-rolled, in the standard size range and at volume. Welded becomes competitive when the size is outside the standard series, the quantity is small, or the plate grade is not available as a rolled section.
Cross-sectional area in mm² × 7.85 ÷ 1,000 = kg/m. Use the area from the section table, not an estimate from the depth and width.
EN 10204 3.1 for structural steel, which is a mill certificate tied to the heat number. A 2.2 certificate is a statement of compliance, not test results — fine for secondary members, not for a primary frame.
If you already know the designation and need the steel, send the section list, the grade and the length. We return the weight and a quotation.
