Description
Factory-Direct SHS & RHS Pricing — As a vertically integrated manufacturer with our own steel mill and 3 production lines, we eliminate trader markups on S355JR square and rectangular steel tube orders from 10×10mm to 1000×1000mm.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235B / S355JR Square and Rectangular Steel Tube |
| Product Type | Square & Rectangular Steel Tube (SHS / RHS) |
| Steel Grade | Q235B, Q355, S235JR, S355JR, S355JOH, S355J2H, STK400, SS400, C250, C350, C460, St37, St52, ASTM A500 Grade A/B/C/D |
| Standard | ASTM A500, EN 10219, EN 10210, JIS G3466, AS 1163, GB/T 6728 |
| Section Shape | Square & Rectangular |
| Size Range | Square 10×10mm–1000×1000mm; Rectangular 10×20mm–1100×800mm |
| Wall Thickness | 0.5–60mm |
| Length | 1–24m |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Bare, Oiled, Black Painting, Hot-dip Galvanized (zinc coating 30–550g/m²), Color Painting |
| Tolerance | ±1% (dimensional) |
| Ends | Plain End |
| Processing Service | Cutting, Bending, Punching, Decoiling |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC & General Construction | Steel frame structures for warehouses, industrial buildings, and commercial complexes |
| Machinery & Equipment | Machinery bases, equipment support frames, and industrial platforms |
| Infrastructure | Fencing posts, guard rails, and highway sound barriers |
| Agriculture | Greenhouse structural frames and irrigation support systems |
| Storage & Logistics | Shelving racking systems and mezzanine floor structures |
Where Negative Tolerance Turns a Cheap Quote Into an Expensive Rework
Dimensional deviation beyond ±1% tolerance forces on-site re-cutting and weld joint misalignment on structural frames.
When buyers source S355JR square and rectangular steel tube from traders who consolidate from multiple small mills, wall thickness often drifts below the ordered specification — sometimes by 8–12% on thin-wall sections. The material arrives with certificates that look valid, but actual measurements on the dock reveal a different story. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed hollow sections] This creates cascading costs: connection plates don’t align, bolt holes miss, and the structural engineer must re-evaluate load capacity. On a recent warehouse project in Southeast Asia, a 40-container order of 150×150×5mm RHS had to be sorted by actual thickness — 30% of the tubes were rejected at site inspection.
How ERW Square and Rectangular Tubes Fit Structural Frame Engineering
S355JR square and rectangular steel tube produced by ERW process delivers consistent weld seam integrity across the full 10×10mm to 1000×1000mm size range, making it suitable for primary and secondary structural members in building frames. The ±1% dimensional tolerance ensures that connection details — end plates, gussets, and bolted joints — fit as designed without field modification. For EPC projects requiring mixed steel grades across EN, ASTM, and JIS standards, sourcing from a single integrated mill eliminates the certification gaps that occur when tubes arrive from different production batches.
Structural Compliance and Surface Protection Selection
Engineering codes such as EN 1993 and AISC 360 require verified material properties for load-bearing hollow sections — S355JR square and rectangular steel tube meeting EN 10219 provides the documented yield strength and chemistry that structural engineers specify. [NEED_CITE: EN 10219 cold-formed structural hollow section compliance] Surface treatment selection depends on the exposure environment: bare or oiled tubes suit indoor structural frames where painting occurs on-site; hot-dip galvanized coatings from 30–550g/m² protect outdoor infrastructure like fencing and guard rails against atmospheric corrosion; black painting or color coating serves architectural applications where appearance matters. For EU-bound projects, CE certification under EN 10210/EN 10219 is mandatory for customs clearance — without it, containers get held at port regardless of material quality.
Steel Grade Equivalence and ERW Process Fundamentals
The S-series (S235JR, S355JR, S355J2H) follows European EN standards with increasing yield strength grades suited for heavier structural loads, while Q235B and Q355 represent the Chinese GB system with similar mechanical hierarchies. ASTM A500 Grade B and C serve North American projects with different chemistry and testing requirements. ERW welding produces a continuous longitudinal seam with high metal utilization and consistent quality — unlike seamless tubes, ERW offers cost advantages for structural applications where internal pressure is not a factor. The process supports lengths up to 24m, reducing the number of field welds on long-span structures. [NEED_CITE: steel grade equivalence between EN 10219 and ASTM A500 standards]
Hot-dip galvanizing at 30–550g/m² zinc coating provides corrosion protection proportional to the environment severity — C2 indoor environments need minimal coating, while C4–C5 industrial or coastal zones demand the upper range. Wall thickness tolerance directly affects theoretical weight calculations: a 100×100×5mm SHS ordered at 5.0mm actual thickness weighs differently than one delivered at 4.6mm, and invoicing by theoretical weight versus actual weight creates significant cost variance on large orders.
The Hidden Cost of Unverified Material Certificates
Pricing that seems attractive often reflects tolerance shortcuts or certificate forgery — the real cost appears during structural inspection or customs clearance.
When S355JR square and rectangular steel tube arrives without traceable heat numbers linking back to the original billet, the entire batch becomes questionable. [NEED_CITE: material traceability requirements for structural steel certification] Engineering inspectors reject components lacking proper mill test certificates, causing project delays and forcing replacement orders at premium prices. In EU markets, missing CE documentation under EN 10219 means containers cannot clear customs — the cargo sits at port accumulating demurrage charges while the buyer scrambles to source compliant material. The structural safety implications are even more serious: tubes with actual yield strength below the specified S355JR minimum compromise the load capacity of the entire frame, creating liability exposure that no amount of cost savings can justify.
Why Integrated Mill Production Matters for Your Project
Our own steel mill with 3 production lines and 2,800+ raw material specifications means every S355JR square and rectangular steel tube traces back to billet produced in-house — no third-party material with uncertain chemistry enters our production. The in-house laboratory tests chemical composition and mechanical properties for every heat, generating mill test certificates with full traceability. We hold CE certification for EN 10210/EN 10219 structural hollow sections, ISO 9001 quality management, and welcome third-party inspection from SGS, BV, or TÜV before shipment. For projects requiring mixed standards — say S355JR for the main frame and ASTM A500 for secondary members — we produce both from the same facility under unified quality control.
I’ve seen what happens when loading goes wrong. On a 25×25mm black square tube shipment to Dubai, we skipped proper internal bracing in the container. The bottom layer tubes crushed under the weight during ocean transit — the entire batch deformed and the client rejected it. That loss taught me to oversee loading with the same intensity as production. Today, every container of S355JR square and rectangular steel tube gets proper dunnage, edge protectors for galvanized surfaces, and strategic weight distribution to prevent deformation during the voyage.
Documentation & Compliance
- Mill test certificate documenting S355JR chemical composition and mechanical properties per EN 10219, with heat number traceability from our own steel mill
- CE certificate for EN 10219 cold-formed structural hollow sections, required for EU market customs clearance and engineering approval
- ISO 9001 quality management certificate covering the full production process from billet to finished SHS/RHS
- SGS or BV third-party inspection report available for dimensional verification, weld seam testing, and coating thickness measurement
- Material traceability documentation linking each bundle to its original heat number and production batch
- Complete customs documents including packing list, bill of lading, and certificate of origin for import clearance
Packaging, Loading & Delivery
- S355JR square and rectangular steel tubes bundled with steel strips and edge protectors, sized for container loading with proper weight distribution to prevent deformation
- Galvanized SHS/RHS packed with protective separators to preserve the zinc coating during ocean transit, preventing surface scratches that compromise corrosion resistance
- Container loading optimized for the 10×10mm to 1000×1000mm size range, with dunnage and bracing calculated for the specific wall thickness and length ordered
- Custom cutting to project-specified lengths within the 1–24m range, reducing on-site waste and welding requirements
- Each bundle marked with heat number, steel grade (S355JR/Q235B/ASTM A500), dimensions, and production date for site identification
- Delivery terms available as FOB, CIF, or DDP with professional export documentation and tracking until site delivery
Getting Your Quote Started
Share your project drawings (PDF/DWG), required steel grades, dimensions, quantities, and destination port — we respond within 24 hours with pricing, mill test certificate samples, and production lead time. For non-standard sizes or mixed-standard orders, our engineering team reviews shop drawings and provides fabrication recommendations before you commit.
Request Your S355JR Square and Rectangular Steel Tube Quote
Send specifications and quantities to receive pricing with full mill test certificates and CE documentation.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Email: admin@xjystructure.com
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Frequently Asked Questions
Q: How do S355JR, ASTM A500 Grade B, and Q345B compare in chemistry and mechanical properties?
A: These grades follow different standard systems — S355JR meets EN 10219 with specific carbon and manganese limits for weldability; ASTM A500 Grade B follows North American testing protocols; Q345B is the Chinese GB/T 1591 equivalent. We produce all three grades and can provide cross-reference documentation for projects requiring material substitution approval from engineers.
Q: Do you provide EN 10204 3.1 certificates, and can third-party labs re-test?
A: Yes, every shipment includes EN 10204 3.1 mill test certificates with heat number traceability from our own steel mill. Third-party inspection from SGS, BV, or TÜV is available for independent verification of chemical composition and mechanical properties before shipment.
Q: Can you produce non-standard dimensions, and what is the minimum order quantity?
A: We produce custom sizes within the 10×10mm to 1000×1000mm range and 0.5–60mm wall thickness. MOQ depends on the specific dimension and steel grade — contact us with your requirements for exact quantities.
Q: When should I choose galvanized versus painted versus bare tubes?
A: Hot-dip galvanized (30–550g/m² zinc coating) suits outdoor and corrosive environments like infrastructure and coastal projects. Black painting or color coating works for architectural applications. Bare or oiled tubes are appropriate for indoor structural frames where on-site painting occurs after installation.
Q: How does tolerance affect invoicing and shipping cost calculation?
A: Our S355JR square and rectangular steel tube maintains ±1% dimensional tolerance. Invoicing can be by theoretical weight (calculated from ordered dimensions) or actual weight (measured at delivery). Clarify your preference when requesting quotes to avoid cost discrepancies on large orders.
Get Factory-Direct Pricing with Full Certification
Submit your specifications and quantities to receive a detailed quote including material costs, fabrication options, and complete documentation packages.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Email: admin@xjystructure.com
Mobile/WhatsApp/WeChat: +86 188 5315 7756
