GB Q235B, Q345B, Q390, and Q420 steel I-beams are high-strength structural beams widely used in buildings, bridges, industrial facilities, and heavy-load support applications.
GB Q235b / Q345b / Q390 / Q420 Steel I beam
| Material Standard | GB Q235b / Q345b / Q390 / Q420 | Yield Strength |
|
| Dimensions | W8×21 to W24×104 (inches) | Length | Stock for 6 m & 12 m, Customized Length |
| Dimensional Tolerance | Conforms to GB/T 11263 | Quality Certification | EN 10204 3.1 material certification & SGS/BV third-party testing report (tensile and bending tests) |
| Surface Finish | Hot-dip galvanizing, paint, etc. Customizable | Applications | Building Construction,Bridges,Industrial Structures,Marine and Transportation,Miscellaneous |
| Carbon Equivalent | Ceq≤0.45%(Ensure good weldability) Explicitly labeled "Compatible with AWS D1.1 welding code" |
Surface quality | No visible cracks, scars, or folds. Surface flatness: ≤2mm/m Edge perpendicularity: ≤1° |
| Property | Q235B | Q345B | Q390 | Q420 | Advantage / Notes |
|---|---|---|---|---|---|
| Yield Strength | ≥ 235 MPa / 34 ksi | ≥ 345 MPa / 50 ksi | ≥ 390 MPa / 57 ksi | ≥ 420 MPa / 61 ksi | Higher grades provide greater load-bearing capacity |
| Tensile Strength | 370–500 MPa / 54–73 ksi | 470–630 MPa / 68–91 ksi | 490–675 MPa / 71–98 ksi | 540–720 MPa / 78–104 ksi | Q420 offers superior strength for demanding structures |
| Elongation | ≥ 26% | ≥ 20% | ≥ 16% | ≥ 15% | Lower elongation with higher strength; Q235B easier for forming and welding |
| Weldability | Excellent | Excellent | Good | Moderate | All grades are weldable; higher strength steels may require preheating or controlled welding |
| Impact Toughness (–20°C) | — | ≥ 27 J | ≥ 27 J | ≥ 27 J | Q345B and above ensure better toughness in cold conditions |
| Typical Applications | Light structural frames, low/medium-load beams | Medium-load columns, frames, warehouses | Heavy-load beams, machinery support structures | Long-span bridges, high-rise buildings, offshore and industrial steel structures | Choose grade according to design strength, welding needs, and environmental conditions |
| Shape | Depth (in) | Flange Width (in) | Web Thickness (in) | Flange Thickness (in) | Weight (lb/ft) |
| W8×21（Sizes Available） | 8.06 | 8.03 | 0.23 | 0.36 | 21 |
| W8×24 | 8.06 | 8.03 | 0.26 | 0.44 | 24 |
| W10×26 | 10.02 | 6.75 | 0.23 | 0.38 | 26 |
| W10×30 | 10.05 | 6.75 | 0.28 | 0.44 | 30 |
| W12×35 | 12 | 8 | 0.26 | 0.44 | 35 |
| W12×40 | 12 | 8 | 0.3 | 0.5 | 40 |
| W14×43 | 14.02 | 10.02 | 0.26 | 0.44 | 43 |
| W14×48 | 14.02 | 10.03 | 0.3 | 0.5 | 48 |
| W16×50 | 16 | 10.03 | 0.28 | 0.5 | 50 |
| W16×57 | 16 | 10.03 | 0.3 | 0.56 | 57 |
| W18×60 | 18 | 11.02 | 0.3 | 0.56 | 60 |
| W18×64 | 18 | 11.03 | 0.32 | 0.62 | 64 |
| W21×68 | 21 | 12 | 0.3 | 0.62 | 68 |
| W21×76 | 21 | 12 | 0.34 | 0.69 | 76 |
| W24×84 | 24 | 12 | 0.34 | 0.75 | 84 |
| W24×104（Sizes Available） | 24 | 12 | 0.4 | 0.88 | 104 |
Hot Rolled Black:Standard state
Hot-dip galvanizing: ≥85μm , salt spray test ≥500h
Coating: Epoxy primer + topcoat, dry film thickness ≥ 60μm
Application:
For beams and columns in multi-story buildings, industrial plants, warehouses and bridges as the main load‑bearing members. Also good for bridge work, support for heavy machinery, steel flooring, structural retrofitting to increase load carrying ability and stability.
Building Structure
Bridge Engineering
Industrial Equipment Support
Structural Reinforcement
1) Branch Office - Spanish-speaking support, customs clearance assistance, etc.
2) Over 5,000 tons of stock in stock, with a wide variety of sizes
3) Inspected by authoritative organizations such as CCIC, SGS, BV, and TUV, with standard seaworthy packaging
Protection and Packaging: I-beam bundles are terrapack wrapped, reinforced with heat-sealed water-proof sheets, and are accompanied by desicant packs to absorb moisture.
Secure Bundling: Steel bundles 12–16 mm, conforming to the U.S. port lifting standards of 2–3 tons per bundle.
Clear Labeling: Each bundle is labeled in English and Spanish with grade, size, HS code, batch no., and test report.
Large Sections: I-beams ≥800 mm are coated with anti-rust oil and wrapped with tarpaulin.
Trusted Shipping: Long-standing relationships with MSK, MSC, and COSCO enable us to provide dependable schedules and deliver on-time.
QC: All processes conform to ISO 9001 to ensure that you receive the beams in good shape to be able to install your project in a timely manner.
Q: Which standards do your I-beams meet in Central America?
A: Our I-beams meet EN 10025 S235 / S275 / S355 (IPE/IPN) standards, commonly accepted across Central America. We can also supply products compliant with local regulations such as Mexico’s NOM.
Q: What is the delivery time to Panama?
A: Shipping from Tianjin to Colon Free Trade Zone takes about 28–32 days. Including production and customs, total delivery is 45–60 days, with expedited options available.
Q: Do you help with customs clearance?
A: Yes, we cooperate with licensed brokers in Central America to manage customs, taxes, and documentation for hassle-free delivery.
Address
Bl20, Shanghecheng, Shuangjie Street, Beichen District, Tianjin, China
Phone
+86 13652091506
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