Description
Factory-direct galvanized SHS/RHS — vertically integrated steel mill and fabrication facility in Jinan, Shandong, controlling material from raw coil to finished S235/S355 tubes.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S235/S355 Galvanized Square and Rectangular Steel Tube |
| Product Type | Square and Rectangular Steel Tube (SHS/RHS) |
| Steel Grade | St37, S235, S355, Q195, Q235, Q345 |
| Standard | ASTM, EN10219, EN10210, GB/T 6728 |
| Section Shape | Square / Rectangular |
| Size Range | Square and rectangular hollow sections |
| Wall Thickness | 1.2 – 15.7 mm |
| Length | 6m / 6.4m / 12m |
| Technique | Cold Rolled Based / ERW |
| Surface Treatment | Hot Dip Galvanized (Z81-Z120 coating) |
| Tolerance | ±1% |
| Application | Steel structures / Construction frames / Scaffolding / Machinery / Fencing / Industrial platforms |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC & Steel Structure | Building frames, column-beam assemblies, truss systems for industrial plants |
| Construction & Scaffolding | Scaffolding uprights, ledger braces, shoring towers conforming to EN39 |
| Infrastructure & Civil | Highway guardrails, sound barrier supports, bridge handrails |
| Machinery & Equipment | Conveyor frames, machine bases, equipment support structures |
| Fencing & Enclosure | Perimeter fencing posts, gate frames, security barrier systems |
Where Zinc Coating Weight Decides Site Acceptance for Galvanized SHS/RHS
Z81-Z120 hot dip galvanizing determines whether your tubes pass third-party inspection on arrival.
When sourcing EN39 S235 S355 hot dip galvanized square and rectangular steel tube supplier from overseas, coating weight variance is the most common rejection trigger. Buyers specify 60-80 microns average, but fragmented suppliers often deliver 40-50 microns on thinner walls — the exact failure that forces full-container re-galvanizing at destination ports. Our integrated production line controls pickling, fluxing, and galvanizing bath temperature in-house, ensuring Z81-Z120 coating consistency across every S235 and S355 section. [NEED_CITE: hot dip galvanizing coating thickness standards EN ISO 1461]
Matching S235/S355 Galvanized Tubes to Structural Frame Requirements
Galvanized SHS/RHS in S235 and S355 grades serve load-bearing frames where corrosion resistance and structural integrity intersect. The hot dip zinc coating protects weld seams and internal surfaces — critical for scaffolding systems exposed to weather and for industrial platforms in humid environments. Our EN10219 S235 S355 hot dip galvanized square and rectangular steel tube supplier production maintains ±1% wall thickness tolerance, ensuring connection plates fit without field grinding.
Engineering Compliance and Certification for Galvanized Hollow Sections
Structural frames designed to EN 1993 require hollow sections meeting EN10219 cold-formed dimensions and EN10210 welded specifications. S355 grade delivers higher yield capacity for long-span trusses, while S235 suits lighter scaffolding and fencing applications. Hot dip galvanizing to Z81-Z120 provides corrosion protection for 20-50 years depending on environment classification. CE marking under EN10210/EN10219 is mandatory for EU construction projects, and mill test certificates must document heat-by-heat chemical composition and mechanical properties. [NEED_CITE: EN 10219 cold-formed structural hollow sections dimensional tolerances]
Steel Grade Selection and ERW Weld Integrity
S235 and S355 represent European structural steel designations where the number indicates minimum yield strength in MPa. Q235 and Q345 are Chinese equivalents, while ASTM A500 Grade B/C serve North American projects. The ERW welding process produces a longitudinal seam that, when properly heat-treated, matches base metal strength. Cold rolling before welding ensures consistent corner geometry — sharp corners improve connection plate contact and reduce stress concentration at joints. Hot dip galvanizing after forming coats both external and internal surfaces, unlike pre-galvanized strip which leaves weld seams unprotected.
Hidden Costs of Non-Conforming Galvanized Tubes
Ordering EN39 S235 S355 hot dip galvanized square and rectangular steel tube supplier from traders without mill integration creates three failure modes: coating thickness below specification triggers re-galvanizing costs exceeding original material price; wall thickness at negative tolerance极限 reduces load capacity and fails structural calculation verification; missing or forged mill test certificates cause customs holds and project acceptance delays. [NEED_CITE: material certification requirements EN 10204 3.1 3.2 inspection documents]
Procurement Confidence from Integrated Production
XJY Structure operates as the fabrication division of Shandong Xin Jiyuan Special Steel Tube Co., combining raw steel production with downstream processing. This vertical integration means your S235/S355 galvanized SHS/RHS comes from one facility controlling 2,800+ specifications — eliminating the material traceability gap when fabricators source tubes from third-party mills. Our own理化实验室 issues EN 10204 3.1/3.2 mill test certificates documenting chemical composition and mechanical properties per heat number. Third-party inspection by SGS, BV, or TÜV is available before shipment. CE certification under EN10210/EN10219 supports EU customs clearance, while ISO 9001 documentation satisfies quality management requirements. Custom cutting to non-standard lengths and professional container loading optimization reduce site waste and freight costs.
Documentation & Compliance
- Mill test certificate documenting S235/S355 chemical composition and yield strength per EN10219, traceable by heat number
- CE certificate confirming EN10210/EN10219 compliance for galvanized SHS/RHS exported to European Union
- ISO 9001 quality management certificate covering cold rolled ERW welding and hot dip galvanizing processes
- SGS or BV third-party inspection report verifying zinc coating thickness Z81-Z120 and dimensional tolerance ±1%
- Material traceability documentation linking each bundle to heat number, chemical analysis, and mechanical test results
- Customs documents including packing list, bill of lading, and certificate of origin for destination port clearance
Packaging, Loading & Delivery
- Galvanized S235/S355 SHS/RHS bundled with steel strips and edge protectors to preserve zinc coating during ocean transit
- Hot dip galvanized surface protected by waterproof wrapping for 6m/6.4m/12m lengths to prevent white rust formation
- Container loading optimized for 12m long rectangular tubes and 6m square sections, maximizing weight utilization per 20ft/40ft GP
- Custom cutting available for non-standard lengths from 6m/6.4m/12m stock, reducing site cutting waste
- Heat number and steel grade (S235/S355/Q235/Q345) marked on each tube bundle for site identification
- FOB/CIF/DDP terms available with door-to-door logistics coordination for EPC project sites
Request Quotation with Mill Test Certificate
Submit your project drawings, steel grade requirements (S235/S355/Q235/Q345), section dimensions, wall thickness, and coating specification to receive detailed quotation including material, fabrication, galvanizing, and shipping costs. Our engineering team reviews shop drawings within 24 hours and provides mill test certificate samples for your approval before production begins.
Get Factory-Direct Pricing for EN39 S235 S355 Galvanized SHS/RHS
Send your specifications to admin@xjystructure.com or contact via WhatsApp at +86 188 5315 7756 for preliminary assessment and mill test certificate documentation.
Frequently Asked Questions
Q: What is the difference between hot dip galvanized and pre-galvanized SHS/RHS?
A: Hot dip galvanizing immerses finished S235/S355 tubes in molten zinc, coating external and internal surfaces including weld seams with Z81-Z120 thickness. Pre-galvanized tubes are made from galvanized strip, leaving weld seams and cut edges unprotected. Hot dip provides superior corrosion resistance for structural and scaffolding applications.
Q: Can you provide EN 10204 3.2 mill test certificates for S355 grade?
A: Yes, our integrated mill issues EN 10204 3.1 certificates as standard, and EN 10204 3.2 certificates with independent inspector witness are available upon request. Each certificate documents chemical composition and mechanical properties traceable to specific heat numbers.
Q: What steel grade equivalence exists between EN, ASTM, and GB standards?
A: S235 corresponds to ASTM A500 Grade A and Q235; S355 corresponds to ASTM A500 Grade B/C and Q345. We supply all three standard systems and provide equivalence documentation for customs and engineering approval.
Q: What is the minimum order quantity for custom-length galvanized SHS/RHS?
A: Standard lengths are 6m, 6.4m, and 12m. Custom cutting from stock is available with typical minimum order of 5 tons per size. Contact us with your specific length requirements for exact MOQ confirmation.
Q: How do you ensure zinc coating thickness meets project specifications?
A: Our hot dip galvanizing line controls bath temperature, immersion time, and withdrawal speed to achieve Z81-Z120 coating weight. Each production batch undergoes coating thickness testing per EN ISO 1461, and third-party inspection by SGS/BV/TÜV is available before shipment.
Get Your EN39 S235 S355 Galvanized SHS/RHS Quotation Today
Email your project specifications to admin@xjystructure.com or WhatsApp +86 188 5315 7756 to receive factory-direct pricing with complete mill test certificate documentation.
