English 
简体中文 
CN
| Property | Parameter | Description |
|---|---|---|
| Product Name | Square Steel Tube for Construction Projects | Hollow structural section (HSS) with equal-sided square cross-section for structural and architectural use |
| Material Grade | Q235B / Q355B / S235JR / S355J2H / ASTM A500 Gr.B / Gr.C | Q355B equivalent to S355J2H (EN) and A572 Gr.50 (ASTM); suitable for load-bearing construction applications |
| Standard Compliance | GB/T 6728, EN 10219, ASTM A500, JIS G3466 | Cold-formed and hot-formed square hollow sections complying with major international structural standards |
| Chemical Composition (C) | ≤ 0.22% (Q355B) / ≤ 0.26% (A500 Gr.C) | Low carbon content ensures good weldability and formability for construction joints |
| Chemical Composition (Mn) | ≤ 1.60% (Q355B) / ≤ 1.35% (S355J2H) | Manganese enhances tensile strength and toughness in structural hollow sections |
| Chemical Composition (P / S) | P ≤ 0.035% / S ≤ 0.035% | Controlled phosphorus and sulfur levels minimize brittleness and improve impact resistance |
| Tensile Strength | 470–630 MPa (Q355B, per GB/T 1591) / 427–621 MPa (A500 Gr.B) | High tensile strength ensures structural integrity under static and dynamic construction loads |
| Yield Strength | ≥ 355 MPa (Q355B / S355J2H) / ≥ 315 MPa (A500 Gr.B) | Minimum yield strength guarantees resistance to permanent deformation in structural frameworks |
| Elongation | ≥ 20% (Q355B, t ≤ 16 mm) / ≥ 23% (S235JR) | Adequate elongation provides ductility for seismic and impact-resistant construction designs |
| Section Size Range | 20×20 mm – 600×600 mm | Wide size range covers light framing, columns, beams, trusses, and heavy structural applications |
| Wall Thickness | 1.0 mm – 25.0 mm | Thickness selected based on load requirements; heavier walls for primary structural members |
| Length | Standard: 6 m / 12 m; Custom: up to 16 m | Fixed or cut-to-length options available to minimize on-site waste and fabrication costs |
| Surface Finish | Mill finish (black), hot-dip galvanized (≥ 45 µm), painted, or pre-primed | Galvanized finish per ASTM A123 / EN ISO 1461 for corrosion protection in exposed construction environments |
| Application | Building frames, columns, trusses, scaffolding, curtain wall supports, bridges, industrial structures | Widely used in residential, commercial, and infrastructure construction for primary and secondary structural members |
| Certification | ISO 9001:2015, CE Marking (EN 10219), Mill Test Certificate (EN 10204 3.1) | Third-party certified quality management; MTCs traceable to heat number and chemical/mechanical test results |
| Packaging | Bundled in steel strapping (1–3 MT per bundle); wooden dunnage; optional waterproof wrapping | Secure bundling prevents transit damage; packaging customized for container, flat-rack, or bulk shipment |
| MOQ | 5 MT per size / 25 MT mixed order | Flexible MOQ supports project-based procurement; full container load (FCL) pricing available from 25 MT |
Initial shipment had minor labelling inconsistency — resolved satisfactorily
We ordered 50 tonnes of 80×80×6mm Q355B square tubes for resale to fabrication clients. The steel itself tested fine — yield strength confirmed at 370 MPa and wall thickness within tolerance. However, bundle labels on roughly 15% of pieces showed a misprint in the heat number, creating a traceability concern for our clients who require strict ASTM documentation chains. We raised this immediately and the supplier issued corrected certificates within 48 hours and offered a partial credit. Issue was handled professionally. We've since placed a follow-up order with no problems.
We ordered 50 tonnes of 80×80×6mm Q355B square tubes for resale to fabrication clients. The steel itself tested fine — yield strength confirmed at 370 MPa and wall thickness within tolerance. However, bundle labels on roughly 15% of pieces showed a misprint in the heat number, creating a traceability concern for our clients who require strict ASTM documentation chains. We raised this immediately and the supplier issued corrected certificates within 48 hours and offered a partial credit. Issue was handled professionally. We've since placed a follow-up order with no problems.
