Description
Factory-direct S355JR ERW square steel tube — Vertically integrated from raw steel mill to finished welded hollow sections, covering 2,800+ specifications with full material traceability per heat number.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S355JR / Q235B ERW Square Steel Tube |
| Product Type | ERW Welded Square Steel Tube |
| Steel Grade | S235JR, A36, S355, SS400, Q235B |
| Standard | ASTM A500, EN10219, EN10210, JIS G3466, GB/T 6728 |
| Section Shape | Square |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Cold Rolled / Galvanized (optional) |
| Tolerance | ±1% |
| Length | Customized |
| Oiled or Non-oiled | Non-oiled |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Delivery Time | 31 ~ 45 days |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Steel Structure Construction | Factory building frames, stadium roof trusses, commercial center column systems |
| Machinery Manufacturing | Machine tool base frames, automation equipment support structures |
| Infrastructure Construction | Bridge auxiliary structures, greenhouse skeleton frames |
| Home Decor & Furniture | Stair handrail systems, structural furniture frames |
| Vehicle Manufacturing | Trailer chassis frames, recreational vehicle structural skeletons |
Where Dimensional Tolerance Decides Structural Alignment on Site
±1% tolerance on S355JR ERW square steel tube means bolt holes line up without field reaming.
When overseas buyers receive fabricated hollow sections with out-of-tolerance dimensions, the entire assembly sequence collapses. Column-to-beam connections designed for precise fit-up end up requiring costly on-site modifications. Weld prepping becomes guesswork. Project timelines slip while engineering teams issue RFIs back to the fabrication source. For EPC firms managing multi-trade coordination, dimensional inconsistency in raw structural tubes cascades into downstream delays that dwarf the original material cost savings. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]
Matching S355JR Grade to Structural Load Requirements
The S355JR grade in this ERW square steel tube series delivers higher yield capacity than S235JR alternatives, making it suitable for primary load-bearing frames in commercial buildings and industrial facilities where structural engineers specify increased moment resistance. The ERW welding process produces a continuous longitudinal seam with consistent penetration, ensuring torsional stiffness critical for machinery base frames and automation equipment supports. When projects demand corrosion resistance in coastal or chemical plant environments, the optional galvanized surface treatment extends service life without field-applied coating delays. Our vertically integrated supply chain means the same quality system governs both raw steel production and finished tube fabrication — eliminating the traceability gaps that occur when fabricators source materials from third-party mills.
Engineering Compliance Across International Standards
Structural hollow sections must conform to project-specific engineering codes: EN10219 for European construction, ASTM A500 for North American applications, and JIS G3466 for Japanese-spec infrastructure. The S355JR / Q235B ERW square steel tube we produce meets these standards through controlled chemical composition and verified mechanical properties documented in mill test certificates. For projects requiring CE marking under EN10210 or EN10219, our fabrication facility maintains certified welding procedures and qualified welders per AWS and EN standards. Custom length cutting reduces on-site secondary processing, while punching and bending services allow direct delivery of connection-ready components. [NEED_CITE: steel grade equivalence mapping between EN 10219 and ASTM A500 specifications]
Understanding ERW Welding Process and Grade Selection
Electric Resistance Welding forms the longitudinal seam by passing high-frequency current through the steel strip edges, creating a forge weld without filler metal. This process suits square and rectangular hollow sections where the weld seam runs parallel to the tube axis, producing consistent corner geometry essential for moment-resisting connections. The S355JR grade offers higher yield strength than S235JR, allowing engineers to reduce section sizes while maintaining load capacity — a critical factor when shipping costs favor lighter structures. Q235B serves projects following Chinese national standards, while SS400 meets Japanese industrial requirements. The ±1% dimensional tolerance ensures that theoretical weight calculations align with actual delivered mass, preventing budget overruns on tonnage-based contracts.
Hidden Costs of Unverified Material Certification
Purchasing structural tubes without verified mill test certificates creates cascading risks: customs authorities in EU markets may detain shipments lacking CE documentation per EN10219; project inspectors reject components without heat-number traceability; and structural engineers cannot approve load calculations without certified mechanical properties. Material substitution — receiving S235JR when S355JR was specified — compromises structural safety margins and triggers costly replacement cycles. Third-party inspection by SGS or BV validates chemical composition and dimensional accuracy before shipment, protecting buyers from quality disputes after ocean transit. [NEED_CITE: material certification requirements for structural steel imports under EU Construction Products Regulation]
Why Project Procurement Teams Source S355JR ERW Square Steel Tube From Us
Our fabrication division operates under the same corporate entity as the raw steel mill, meaning material procurement, tube forming, welding, and quality inspection occur within one controlled environment. This vertical integration eliminates the communication gaps and certification chain breaks that plague fragmented supply arrangements. We maintain inventory across 2,800+ specifications, enabling consolidated shipments that combine multiple sizes and grades into single container loads — reducing logistics costs for projects requiring diverse section profiles. Every bundle carries heat-number identification linking back to original slab chemistry, supporting full material traceability from mill to job site. Our loading teams develop custom stowage plans for each shipment, preventing the damage that occurs when hollow sections are stacked without proper support during ocean transit. Third-party inspection services coordinate directly with SGS or BV surveyors at our facility, streamlining pre-shipment verification for international buyers.
Documentation & Compliance
- Mill test certificate documenting S355JR chemical composition and yield strength per EN10219, including heat number traceability
- CE certificate confirming compliance with EN10210 and EN10219 for structural hollow sections in European construction markets
- ISO 9001 quality management system certificate covering the integrated steel production and tube fabrication process
- SGS or BV third-party inspection report verifying dimensional accuracy, weld seam quality, and surface treatment thickness
- Material traceability documentation linking each bundle to original steel slab chemistry and rolling records
- Complete customs documentation package including packing list, bill of lading, and certificate of origin for import clearance
Packaging, Loading & Delivery
- S355JR ERW square steel tubes bundled with high-tensile steel straps, separated by timber spacers to prevent surface scratching during transit
- Galvanized finish tubes wrapped with protective film at corners to preserve zinc coating integrity during ocean shipping
- Custom length tubes (up to 12 meters) loaded with optimized stowage plans maximizing container utilization while maintaining weight distribution
- Heat number and steel grade stenciled on each bundle tag, enabling rapid identification at project site without unpacking
- Non-oiled surface condition suitable for immediate welding or painting upon arrival, eliminating degreasing preparation steps
- FOB, CIF, and DDP delivery terms available with door-to-door logistics coordination for oversized structural tube shipments
Initiating Your S355JR ERW Square Steel Tube Inquiry
Submit your project specifications including steel grade requirements, section dimensions, total tonnage, and destination port to receive a detailed quotation with production timeline. Our engineering team reviews shop drawings to confirm dimensional compatibility and suggests optimizations for fabrication efficiency. We provide mill test certificates and third-party inspection coordination as standard documentation for international structural steel procurement.
Request Quotation with Mill Test Certificate
Send your technical specifications and quantity requirements to receive pricing, delivery schedule, and material certification documentation within 24 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: What is the difference between S355JR and S235JR grades for structural applications?
A: S355JR provides higher yield strength than S235JR, allowing engineers to specify smaller section sizes while maintaining structural load capacity. This grade selection affects both material cost and shipping weight calculations for international projects.
Q: Can you provide third-party inspection before shipment?
A: Yes, we coordinate SGS or BV inspection services at our facility to verify dimensional accuracy, weld quality, and surface treatment before container loading. Inspection reports become part of your shipping documentation package.
Q: What surface treatment options are available for corrosion protection?
A: We offer cold rolled finish for indoor applications, hot-dip galvanized coating for outdoor or corrosive environments, and non-oiled condition for projects requiring immediate welding or field painting.
Q: How do you ensure material traceability across the supply chain?
A: Each tube bundle carries a heat number tag linking to the original steel slab chemistry and rolling records. Mill test certificates document chemical composition and mechanical properties for every production batch.
Q: What is the typical production lead time for custom length orders?
A: Standard production schedules range from 31 to 45 days depending on order volume and specification complexity. Rush production available for urgent project requirements with advance coordination.
Get Your S355JR ERW Square Steel Tube Quote Today
Share your project drawings and material specifications to receive competitive pricing with full mill test certification and international standard compliance documentation.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
