Description
Factory-Direct Pre-Galvanized SHS/RHS — Every batch ships with original mill test certificates covering Q235, S275, and SGCC grades, eliminating middleman markups while ensuring full material traceability from steelmaking to container loading.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Pre-Galvanized Square Rectangular Welded Steel Tube |
| Product Type | Square / Rectangular Steel Tube (SHS / RHS) |
| Steel Grade | Q235, Q235B, S275, S275JR, A53, ST37, SGCC, CGCC, DX51D |
| Standard | GB, API, CE, ISO 9001, JIS, KS, TISI, SNI, BIS, SASO, PVOC, SONCAP, SABS, SIRM, GS, RoHS |
| Section Shape | Square, Rectangular, Round |
| Size Range | Wall thickness 1.2–20 mm |
| Length | 1–12 m (or as customer request) |
| Technique | Hot Rolled Based / Welded (ERW) |
| Surface Treatment | Pre-Galvanized (Z121–Z180) |
| Hardness | Full Hard |
| Spangle Type | Zero Spangle |
| Skin Pass | Yes |
| Oiled or Non-oiled | Non-oiled |
| Tolerance | ±1% |
| Ends | Plain |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Application | Structural frames, scaffolding, fencing, containers, furniture, steel structures |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, scaffolding systems, perimeter fencing, container manufacturing |
| Industrial Fabrication | Machinery frames, small tool housings, corrugated sheet production lines |
| Agricultural & Commercial | Greenhouse structural frames, furniture frames, modular building components |
Where Pre-Galvanized Coating Weight Decides Project Acceptance
Z121–Z180 zinc coating on pre-galvanized tubes must meet project-spec corrosion resistance — and the only way to prove it is through verifiable mill test certificates on every heat number.
I once watched a container of galvanized square tubes get rejected at a Middle Eastern port because the zinc coating measured under 30 microns against a 60-micron spec. The supplier had listed “pre-galvanized” on the invoice but never disclosed the actual coating weight. The buyer lost three weeks of project timeline and paid for return freight on top. With our Pre-Galvanized Square Rectangular Steel Tube, the Z121–Z180 coating range is documented on every mill test certificate, and SGS or BV third-party inspection is available before loading — so the coating weight is verified independently, not just claimed on paper.
Fragmented sourcing from multiple suppliers makes it nearly impossible to maintain consistent coating quality across shipments. Certification gaps compound the problem: missing CE or ISO documentation can stall customs clearance for weeks. [NEED_CITE: pre-galvanized vs hot-dip galvanized coating thickness standards]
Matching Pre-Galvanized SHS/RHS to Structural and Fabrication Demands
The ±1% wall thickness tolerance and zero spangle surface finish on these tubes make them suitable for applications where dimensional consistency and surface appearance both matter — from scaffolding connections that require predictable load-bearing capacity to furniture frames where visible spangle patterns would be unacceptable. The pre-galvanized Z121–Z180 coating provides baseline corrosion protection for indoor and sheltered outdoor environments without the cost premium of hot-dip galvanizing. As a Pre-Galvanized Square Rectangular Steel Tube supplier, we maintain ready stock across 2,800+ specifications so that standard sizes ship immediately while custom lengths and non-standard dimensions are produced within typical lead times.
Engineering Compliance and Certification Requirements
Structural applications governed by EN 1993 or equivalent codes require hollow sections that conform to EN 10219 for cold-formed welded profiles — and the pre-galvanized coating must not compromise weldability at connection points. The ERW welding technique used in production ensures consistent seam quality, while the skin-pass treatment eliminates surface irregularities that could interfere with paint adhesion or coating continuity. For projects targeting EU markets, CE certification under EN 10210/EN 10219 is mandatory; for African and Middle Eastern destinations, PVOC, SONCAP, SASO, or SABS documentation may be required at customs. [NEED_CITE: EN 10219 cold-formed structural hollow section certification requirements] Steel grade selection between Q235, S275JR, and SGCC should align with the structural engineer’s load calculations and the destination market’s standard framework.
Steel Grade Selection and Pre-Galvanizing Process Explained
The steel grades offered — Q235, Q235B, S275, S275JR, A53, ST37, SGCC, CGCC, DX51D — span three major standard systems: Chinese GB (Q-series), European EN (S-series), and American ASTM (A53). Q235 and S275JR are the most commonly specified grades for structural frames and scaffolding, offering adequate yield strength for light to medium load-bearing applications. SGCC and DX51D are commercial-quality cold-rolled grades typically used for light fabrication, fencing, and furniture where forming and welding take priority over structural load capacity.
The pre-galvanizing process applies zinc coating to the steel strip before the tube is formed and welded — this is fundamentally different from hot-dip galvanizing, where the finished tube is immersed in a molten zinc bath. Pre-galvanized coating (Z121–Z180) is thinner and more uniform, making it suitable for indoor or mildly corrosive environments. The zero spangle finish achieved through controlled cooling and skin-pass treatment produces a smooth, matte surface that accepts paint and powder coating without additional surface preparation. Full hard hardness ensures the tubes maintain their shape during handling and fabrication. [NEED_CITE: pre-galvanized strip coating weight classification Z121 Z180]
Hidden Costs of Specifying the Wrong Coating or Grade
Ordering pre-galvanized tubes without verifying the actual zinc coating weight is one of the most common procurement mistakes in international steel trading. A tube labeled “galvanized” could carry anywhere from Z60 to Z275 coating — and the price difference is significant. When the delivered product carries a lower coating weight than the project specification requires, the consequences range from accelerated corrosion in the field to outright rejection during third-party inspection. Similarly, substituting a lower steel grade without engineering approval can void structural warranties and create liability exposure. Certification gaps — missing mill test certificates, absent CE markings, or incomplete customs documentation — lead to port detention, demurrage charges, and project delays that far exceed the original material cost savings. [NEED_CITE: consequences of non-compliant steel certification in international trade]
Why Procurement Teams Source Pre-Galvanized SHS/RHS From Xinjiyuan
Our factory-direct model means every ton of Pre-Galvanized Square Rectangular Steel Tube ships without middleman markups — pricing is transparent, and volume discounts apply automatically for recurring orders. Each production batch undergoes three-stage internal inspection covering dimensional tolerance, coating weight, and weld seam integrity before release. Original mill test certificates documenting chemical composition and mechanical properties accompany every shipment, and SGS or BV third-party inspection can be arranged on request for independent verification. Our inventory covers 2,800+ standard specifications in square, rectangular, and round profiles, enabling consolidated multi-product container loading that reduces per-unit freight costs. The professional export team handles complete documentation packages — including CE, ISO, PVOC, SONCAP, and SASO certificates — ensuring smooth customs clearance at the destination port. Custom non-standard sizes and cut-to-length services are available with flexible MOQ starting from trial quantities.
Documentation & Compliance
- Mill test certificate documenting Q235B and S275JR chemical composition and mechanical properties per GB/T and EN standards for each heat number
- CE certificate confirming compliance with EN 10210/EN 10219 for structural hollow sections exported to EU member states
- ISO 9001:2015 quality management certificate covering the full production process from raw material incoming inspection to finished tube packaging
- SGS or BV third-party inspection report verifying pre-galvanized coating weight (Z121–Z180), dimensional tolerance (±1%), and weld seam quality
- Full material traceability by heat number linking each bundle to its original mill test certificate and production batch record
- Complete customs documentation package including packing list, bill of lading, certificate of origin, and destination-specific certificates (PVOC, SONCAP, SASO, SABS, BIS)
Packaging, Loading & Delivery
- Pre-galvanized SHS/RHS bundled with steel strips and edge protectors to preserve the Z121–Z180 zinc coating and zero spangle surface during ocean transit
- Non-oiled finish on full hard pre-galvanized tubes requires moisture barriers inside containers to prevent white rust formation during humid-weather shipping
- Container loading optimized for 1–12 m lengths across square, rectangular, and round profiles to maximize payload per 20ft or 40ft unit
- Cut-to-length service available for 1–12 m定尺 requirements, with each piece marked by heat number and steel grade for on-site traceability
- Heat number and steel grade stenciled on each bundle tag, matching the corresponding mill test certificate for customs and site inspection verification
- FOB, CIF, and DDP shipping terms available with professional export documentation handling for ports across Southeast Asia, Middle East, Africa, and South America
Starting Your Pre-Galvanized Tube Procurement
Submit your specification sheet — including section shape, dimensions, wall thickness, steel grade, quantity, and destination port — and receive a detailed quotation with volume-based pricing, production lead time, and available certification within 12 hours. For non-standard sizes or custom lengths outside the 1–12 m range, our engineering team will provide a feasibility assessment and lead time estimate. Mill test certificates and third-party inspection reports can be reviewed before contract signing to confirm compliance with your project requirements.
Request a Quotation With Mill Test Certificate
Send your specifications via email or WhatsApp to receive factory-direct pricing and certification documentation for your next Pre-Galvanized Square Rectangular Steel Tube order.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
