What is W8x31 structural H beam?
W8×31 structural H beam belongs to the high-strength low-alloy steel (HSLA) family, with a minimum yield strength of ≥50,000 psi (approximately 345 MPa). It has a nominal section depth of around 8 inches and a unit weight of 31 lb/ft.
The beam is produced through a hot-rolling process to achieve standard geometric dimensions, featuring a parallel and wide flange cross-section. Its surface has a typical industrial matte appearance, either in mill finish condition or with additional corrosion protection treatment.
Designed for heavy-load structural applications, it does not require a decorative surface finish and is commonly used in industrial buildings, bridge support structures, equipment support frames, and similar heavy-duty steel applications.
Gnee can stably supply W8×31 Wide Flange Beams with hot-rolled production and various corrosion protection options. According to different load requirements and service environments, the most common steel grades include:
ASTM A36 (Carbon Structural Steel):
A cost-effective structural steel with excellent weldability, widely used in general building frames, secondary beams, and conventional steel structures.
ASTM A572 Grade 50 (High-Strength Low-Alloy Steel):
Featuring a minimum yield strength of 50 ksi (345 MPa), approximately 38% higher than A36 steel, A572 Gr50 provides a superior strength-to-weight ratio for industrial buildings, equipment supports, and heavy-duty structures.
ASTM A588 (Weathering Steel):
Containing corrosion-resistant alloying elements such as copper (Cu 0.20–0.40%), chromium (Cr 0.40–0.80%), and nickel (Ni 0.25–0.65%), A588 forms a stable protective patina layer in outdoor environments, making it ideal for bridges, architectural structures, and exposed steel applications.
Gnee provides complete quality assurance services, including Mill Test Certificates (MTC), chemical composition analysis, mechanical property testing, dimensional inspection, and third-party inspection reports from SGS, BV, or TÜV upon request.
W8x31 structural H beam Specification
| Item | Specification |
|---|---|
| Standard | ASTM |
| Grade | ASTM A572 Grade 50, ASTM A36, ASTM A588 |
| Section Type | W8×31 Wide Flange Beam |
| Manufacturing Process | Hot Rolled |
| Nominal Depth (d) | 8.00 in (203 mm) |
| Flange Width (bf) | 8.00 in (203 mm) |
| Web Thickness (tw) | 0.285 in (7.2 mm) |
| Flange Thickness (tf) | 0.435 in (11.0 mm) |
| Unit Weight | 31 lb/ft (46.1 kg/m) |
| Cross-sectional Area | 9.13 in² (58.9 cm²) |
| Length | 20 ft / 40 ft (6 m / 12 m) or Customized |
| Surface Treatment | Mill Finish, Hot-Dip Galvanized, Painted, or Other Anti-Corrosion Coatings |
| Appearance | Dark gray metallic surface with industrial mill finish; available with protective coatings |
| Main Applications | Industrial buildings, steel frames, equipment support structures, pipe racks, platforms, bridges support structures, and heavy-duty construction projects |
| Certification | Mill Test Certificate (MTC), Chemical Composition Report, Mechanical Property Test Report, Dimensional Inspection Report |
Chemical Composition of W8×31 Wide Flange Beam
| Element | ASTM A36 (%) | ASTM A572 Grade 50 (%) | ASTM A588 (%) |
|---|---|---|---|
| Carbon (C) | ≤0.26 | ≤0.23 | ≤0.19 |
| Manganese (Mn) | - | ≤1.35 | 0.80–1.25 |
| Silicon (Si) | ≤0.40 | ≤0.40 | 0.30–0.65 |
| Phosphorus (P) | ≤0.04 | ≤0.04 | ≤0.04 |
| Sulfur (S) | ≤0.05 | ≤0.05 | ≤0.05 |
| Copper (Cu) | ≥0.20 (when specified) | - | 0.20–0.40 |
| Chromium (Cr) | - | - | 0.40–0.80 |
| Nickel (Ni) | - | - | ≤0.40 |
| Vanadium (V) | - | ≤0.15 | ≤0.10 |
| Columbium (Niobium, Nb) | - | ≤0.05 | - |
Mechanical Properties of W8×31 Wide Flange Beam
| Property | ASTM A36 | ASTM A572 Grade 50 | ASTM A588 |
|---|---|---|---|
| Yield Strength | ≥36 ksi (250 MPa) | ≥50 ksi (345 MPa) | ≥50 ksi (345 MPa) |
| Tensile Strength | 58–80 ksi (400–550 MPa) | 65 ksi (450 MPa) min | 70 ksi (485 MPa) min |
| Elongation (200 mm) | ≥20% | ≥18% | ≥18% |
| Modulus of Elasticity | 29,000 ksi (200 GPa) | 29,000 ksi (200 GPa) | 29,000 ksi (200 GPa) |
| Density | 7.85 g/cm³ | 7.85 g/cm³ | 7.85 g/cm³ |
| Poisson's Ratio | 0.30 | 0.30 | 0.30 |
| Impact Toughness | Depends on grade and testing requirements | Available according to project requirements | Excellent low-temperature toughness |
What is difference between the W8×31 H Beam(A36 vs ASTM A572 Grade 50 vs ASTM A588)
A36 vs A572 Grade 50: Strength Advantage
For the same W8×31 section size, upgrading from ASTM A36 to ASTM A572 Grade 50 increases the minimum yield strength from 36 ksi (250 MPa) to 50 ksi (345 MPa), representing approximately a 38% improvement in material strength.
Without increasing the beam size or unit weight (remaining at 31 lb/ft), A572 Grade 50 can provide higher load capacity and improved structural efficiency for heavy-duty applications.
A572 Grade 50 vs A588: Weather Resistance Advantage
Both ASTM A572 Grade 50 and A588 have a minimum yield strength of 50 ksi (345 MPa). The main difference is corrosion resistance. A588 contains alloying elements such as copper, chromium, and nickel, allowing it to form a dense protective patina layer that can reduce atmospheric corrosion rates by approximately 50% or more compared with ordinary carbon steel in suitable environments.
A572 Grade 50 requires additional protection, such as hot-dip galvanizing or painting, for long-term outdoor exposure, while A588 can be used in exposed applications where the natural protective rust layer helps reduce maintenance requirements.
Applications of W8×31 Wide Flange Beam
- Industrial building frames, steel columns, and heavy-duty structural supports
- Pipe rack structures, equipment support frames, and mechanical platforms
- Bridge support structures, access walkways, and outdoor steel frameworks
- Solar mounting structures, warehouse buildings, and large-span steel structures
- Heavy equipment foundations, crane support structures, and industrial platforms
- Building frames, floor beams, and secondary structural members
ASTM A572 / A36 / A588 W Shape Wide Flange Beam Stock Sizes
| Size | Weight (lb/ft) | Weight (kg/m) | Depth (in) | Flange Width (in) |
|---|---|---|---|---|
| W4×13 | 13 | 19.3 | 4.16 | 4.06 |
| W5×16 | 16 | 23.8 | 5.01 | 5.00 |
| W6×9 | 9 | 13.4 | 5.90 | 3.94 |
| W6×12 | 12 | 17.9 | 6.03 | 4.00 |
| W6×15 | 15 | 22.3 | 5.99 | 5.99 |
| W8×10 | 10 | 14.9 | 7.89 | 4.00 |
| W8×18 | 18 | 26.8 | 8.14 | 5.25 |
| W8×21 | 21 | 31.3 | 8.28 | 5.27 |
| W8×24 | 24 | 35.7 | 7.93 | 6.50 |
| W8×31 | 31 | 46.1 | 8.00 | 8.00 |
| W10×12 | 12 | 17.9 | 9.87 | 3.96 |
| W10×22 | 22 | 32.7 | 10.17 | 5.75 |
| W10×33 | 33 | 49.1 | 9.73 | 7.96 |
| W12×14 | 14 | 20.8 | 11.91 | 3.97 |
| W12×19 | 19 | 28.3 | 12.16 | 4.03 |
| W12×26 | 26 | 38.7 | 12.22 | 6.49 |
| W12×40 | 40 | 59.5 | 12.19 | 8.00 |
| W14×22 | 22 | 32.7 | 13.74 | 5.03 |
| W14×30 | 30 | 44.6 | 13.84 | 6.73 |
| W14×43 | 43 | 64.0 | 13.66 | 10.03 |
| W16×26 | 26 | 38.7 | 15.69 | 5.50 |
| W16×40 | 40 | 59.5 | 15.88 | 7.99 |
| W18×35 | 35 | 52.1 | 17.70 | 6.00 |
| W18×50 | 50 | 74.4 | 18.00 | 7.50 |
| W21×44 | 44 | 65.5 | 20.66 | 6.50 |
| W24×55 | 55 | 81.8 | 23.57 | 7.00 |
| W24×84 | 84 | 125.0 | 24.10 | 9.02 |
| W30×90 | 90 | 134.0 | 29.66 | 10.50 |
| W36×135 | 135 | 201.0 | 35.85 | 12.00 |
In addition to W8×31 Wide Flange Beam, Gnee also stocks a wide range of W-shape H Beams in various sizes to meet different structural requirements. Customized dimensions, cutting services, and fabrication solutions are available upon request.
Contact now to get W8×31 Wide Flange Beam Stock List
The W8×31 Wide Flange Beam Supplier
NEE has established long-term strategic partnerships with China's top-tier structural steel mills, including Baosteel, Ansteel etc. For high-demand architectural and industrial load-bearing projects requiring W8×31 Wide Flange beams (available in ASTM A36, A572 Gr50, and A588), we guarantee 100% authentic, mill-certified products sourced directly from original manufacturers with full MTC (Mill Test Certificate) traceability.
And we have fully equipped structural steel processing centers to offer a comprehensive range of customization services:
Cutting & Sawing: High-tolerance CNC band saw cutting, plasma cutting, and precision coped joint profiling (specifically optimized for W-shape heavy beam cross-sections).
Surface Treatment: In addition to the standard hot-rolled mill finish, we provide customized anti-corrosion treatments including premium Hot-Dip Galvanizing (HDG to ASTM A123), sandblasting/shot blasting (Sa2.5 standard), and shop primer painting.
Forming & Fabrication: Automated multi-spindle drilling, punching, cambering (pre-deflection bending), and factory welding for stiffener and base plates (ideal for the pre-processing of structural framing columns).
Lead Time for W8×31 H Beam
Standard Stock Items: Constant inventory is maintained for common specifications (e.g., standard W8×31 dimensions, available in ASTM A36 and A572 Gr50 grades).
Delivery: Products can be dispatched from the warehouse and ready for shipment within 3 to 7 working days upon receipt of the advance payment or Letter of Credit (L/C).
Customized / Special Specifications: Production scheduling orders must be placed directly with the steel mills for beams requiring custom length cutting, specific high-grade weathering steel (e.g., ASTM A588), or specialized hot-dip galvanizing and drilling processes.
Delivery: The lead time is typically around 15 to 30 working days.
Testing & Inspection for W8×31 H Beam
MTC (Material Test Certificate): Provides material test certificates compliant with EN 10204 3.1 or 3.2 standards
Ultrasonic Testing (UT): For W8×31 beams used in heavy load-bearing structural frames, UT can be performed upon request to ensure internal integrity and freedom from lamellar tearing defects.
Coating and NDT Tests (for Galvanized/Welded Beams): Magnetic coating thickness gauges audit hot-dip galvanized layer thickness (ASTM A123), while Magnetic Particle Testing (MT) or Penetrant Testing (PT) ensures welding seam integrity for pre-fabricated stiffeners.
GNEE Internal Inspection: Prior to dispatch, our quality inspectors conduct a rigorous final verification on each batch, checking beam straightness (camber and sweep), flange-to-web perpendicularity, dimensional tolerances (ASTM A6/A6M), and the removal of sharp edge burrs.
Packaging and Logistics
Heavy-Duty Steel Strapping: W8×31 H-beams are secured into tight, rigid bundles using high-tensile steel bands. Heavy-duty rubber or plastic protective cushions are inserted at all strap contact points to prevent surface abrasion and edge deformation.
Rust-Preventative Encapsulation: For export or long-distance transit, the bundles can be fully wrapped in heavy-duty weatherproof materials (such as waterproof plastic film or VCI anti-rust paper) to seal out moisture, marine salt spray, and industrial contaminants.
Fumigated Timber Skids and Bracing: Export shipments are supported by IPPC-certified, fumigated solid wood skids or thick timber blocks. Bundles are nested securely and separated by wooden spacers to prevent metal-to-metal collision, bending, or shifting during crane handling and maritime stacking.
Weatherproof Tagging and Traceability: Each bundle is securely fastened with corrosion-resistant stainless steel or weatherproof aluminum tags detailing the heat number, dimensions, length, and steel grade (e.g., A36, A572 Gr50, A588), ensuring 100% on-site traceability.
