Description
Factory-direct hot-dipped galvanized SHS & RHS — produced from our own steel mill to finished hollow sections under one integrated quality system.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235B / S275JR Galvanized Square Rectangular Hollow Section |
| Product Type | Galvanized Square / Rectangular Steel Tube (Hollow Section) |
| Steel Grade | Q235, Q235B, Q195, Q355, S275, S275JR, A53, ST37, SGCC, CGCC, DX51D |
| Standard | ASTM, JIS |
| Section Shape | Square / Rectangular |
| Wall Thickness | 1.2 – 20 mm |
| Length | 1 – 12 m (or as customer request) |
| Technique | Hot Rolled Based / ERW |
| Surface Treatment | Hot Dipped Galvanized / Pre-Galvanized (Z30 – Z180) |
| Tolerance | ±1% |
| Hardness | Full Hard |
| Spangle Type | Zero Spangle |
| Skin Pass | Yes |
| Oiled or Non-oiled | Non-oiled |
| Invoicing | By theoretical weight |
| Processing Service | Bending, Cutting, Decoiling, Punching, Welding |
| Application | Steel structures, construction frames, making pipes, cutting sheets, making container, making corrugated sheets, making fences, making small tools, boiler pipe |
| MOQ | 15 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Steel frame structures, columns, beams, platforms for commercial and industrial buildings |
| EPC & Industrial Projects | Support structures for warehouses, logistics centers, and renewable energy installations |
| General Fabrication | Fencing, container frames, corrugated sheet purlins, and small tool manufacturing |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A ±1% tolerance on a 1.2–20 mm range means the difference between a clean weld joint and a rejected connection.
When EPC buyers source galvanized hollow sections from fragmented suppliers, wall thickness often drifts beyond declared tolerance — and the cost shows up on site, not at the mill. Connection plates don’t sit flush, bolt holes misalign, and welding procedures qualified on nominal thickness fail inspection. On a recent West African warehouse project, a batch of RHS arrived with actual wall thickness 0.3 mm below spec on the flat faces; the structural engineer rejected 40% of the columns before first weld. [NEED_CITE: EN 10219 cold-formed hollow section requirements] Material traceability gaps compound the problem — without heat-number linkage to mill test certificates, buyers cannot prove compliance to EN 1090 or AISC auditors.
Matching Galvanized SHS & RHS to Structural Frame and EPC Applications
Hot-dipped galvanized square and rectangular hollow sections in Q235B and S275JR carry zinc coatings from Z30 to Z180, giving engineers a corrosion-resistance range that covers both indoor warehouse purlins and outdoor infrastructure columns. The zero-spangle finish with skin-passed flatness means exposed architectural frames do not require additional painting for aesthetic acceptance. Our in-house bending, cutting, and punching services let EPC firms receive connection-ready components rather than raw lengths — reducing site rework and welding qualification scope.
Engineering Compliance Across EN, ASTM, and JIS Frameworks
Structural hollow sections in S275JR must meet the dimensional and tolerance requirements of EN 10219 for European projects, while Q235B and A53 serve ASTM-governed markets in North America and the Middle East. [NEED_CITE: steel grade equivalence between EN and ASTM standards] Hot-dipped galvanizing thickness must be verified against ISO 1461 or ASTM A123 depending on the project specification — and third-party inspection reports from SGS or BV are routinely required before customs clearance in EU and African ports. The ±1% tolerance on wall thickness and the skin-pass process ensure that shop drawings prepared to EN 1090 or AISC standards translate directly to fabrication without field adjustments.
Steel Grade Selection and Galvanizing Process Explained
Q235B and S275JR represent two different standard systems — Chinese GB and European EN — but both serve as general structural grades with weldable carbon equivalents suitable for hot-dipped galvanizing. Q355 steps up to higher yield strength for heavier load-bearing frames, while SGCC and DX51D are cold-forming grades typically specified for lighter gauge pre-galvanized sections. The hot-dipped process immerses formed tubes in molten zinc, producing a metallurgical bond that covers external and internal surfaces — critical for hollow sections where internal corrosion cannot be inspected. Pre-galvanized (Z30–Z180) uses zinc-coated coil as feedstock, offering lower coating mass but better surface uniformity for cosmetic applications. [NEED_CITE: hot-dipped vs pre-galvanized zinc coating comparison] Wall thickness from 1.2 mm to 20 mm spans light-gauge purlins to heavy structural columns, and the ERW or hot-rolled-based technique is selected based on section size and load requirement.
Hidden Costs of Procuring the Wrong Grade or Coating
Specifying Q235B on a drawing that calls for S275JR may pass visual inspection at the port but fail structural audit under EN 1993 loading calculations — forcing full replacement at project cost. [NEED_CITE: structural steel grade substitution risks in EN 1993] Pre-galvanized tubes substituted for hot-dipped in a coastal environment will show white rust within months, triggering warranty claims and reputational damage for the contractor. Missing heat numbers on mill test certificates mean customs authorities in Nigeria or Saudi Arabia can hold shipments for weeks, demurrage accumulating daily.
Why EPC Buyers Source This Hot Dipped Galvanized Square Rectangular Hollow Section Supplier Through XJY Structure
Our vertically integrated mill and fabrication workshop means every galvanized SHS or RHS is traceable from raw coil to finished bundle — no third-party steel sourcing gaps. We hold EN 10210 / EN 10219 CE certification and ISO 9001, with an in-house laboratory that re-tests chemical composition and mechanical properties before release. Over 2,800 specifications in stock cover non-standard dimensions that would otherwise require minimum-order mill runs. Every shipment includes complete documentation — WPS, PQR, dimensional reports, coating thickness measurements — prepared to the standard your project auditor requires. Professional loading plans for oversized RHS ensure container utilization without damaging the galvanized surface.
Documentation & Compliance
- Mill test certificate documenting Q235B / S275JR chemical composition and mechanical properties per heat number, conforming to EN 10204 3.1
- CE certificate covering EN 10219 cold-formed welded structural hollow sections for EU market customs clearance
- ISO 9001 quality management certificate for the integrated steel mill and fabrication workshop
- SGS or BV third-party inspection report verifying zinc coating thickness and dimensional tolerance before shipment
- Full material traceability from raw coil heat number through forming, welding, and galvanizing stages
- Export documentation including packing list, bill of lading, and certificate of origin for destination-country customs
Packaging, Loading & Delivery
- Hot-dipped galvanized Q235B and S275JR tubes bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit
- Zero-spangle surface wrapped with waterproof paper and plastic film to prevent white rust formation in humid container environments
- 6 m and 12 m lengths loaded with optimized container plans for square and rectangular sections, maximizing payload within weight limits
- Custom cutting to project-specified lengths from the 1–12 m range, with cut ends deburred and marked with heat number and steel grade
- FOB, CIF, and DDP shipping terms available, with door-to-door logistics coordination for EPC project sites in Africa and the Middle East
Requesting a Quotation for Your Galvanized Hollow Section Project
Share your project drawings, steel grade requirement (Q235B, S275JR, or Q355), section dimensions, wall thickness, and coating specification — we respond within 24 hours with pricing, mill test certificate samples, and a production schedule. For non-standard sizes or custom cutting, our engineering team will confirm feasibility and lead time before you commit.
Start Your Hot Dipped Galvanized Square Rectangular Hollow Section Inquiry
Send your specifications, quantities, and destination port to receive a detailed quotation with full material certification.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Frequently Asked Questions
Q: What is the difference between Q235B and S275JR for structural hollow sections?
A: Q235B is a Chinese GB standard grade, while S275JR is a European EN standard grade. Both are general structural carbon steels with similar weldability, but S275JR offers a higher minimum yield strength and is specified for EN 10219 and EN 1090 compliant projects. We supply both grades with full mill test certificates for your project specification.
Q: How do you ensure material traceability from raw coil to finished galvanized tube?
A: Every batch is traced from the raw coil heat number through forming, ERW welding, hot-dipped galvanizing, and final inspection. The mill test certificate references the original heat number, and third-party inspectors from SGS or BV can verify the chain before shipment.
Q: What is the difference between hot-dipped galvanized and pre-galvanized hollow sections?
A: Hot-dipped galvanizing immerses the finished tube in molten zinc, producing a thick metallurgical coating that covers both external and internal surfaces — ideal for outdoor and corrosive environments. Pre-galvanized tubes are made from zinc-coated coil, offering a thinner and more uniform coating suitable for indoor or cosmetic applications. We supply both options in Z30 to Z180 coating masses.
Q: Can you produce non-standard dimensions and what is the minimum order quantity?
A: Yes, our integrated mill and fabrication workshop can produce custom sizes within the 1.2–20 mm wall thickness and 1–12 m length range. The standard MOQ is 15 tons, but we can discuss smaller quantities for project-specific requirements.
Q: What export documentation do you provide for customs clearance?
A: We provide mill test certificates (EN 10204 3.1), CE certificates for EN 10219 compliance, ISO 9001 quality certificates, packing lists, bills of lading, and certificates of origin. Third-party inspection reports from SGS, BV, or Intertek are available upon request before shipment.
