Description
Factory-Direct ERW Square Tubes — S235JR and S355JR grades produced to EN 10219 and ASTM A500, shipped with CE certification and mill test certificates from our Jinan facility.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S235JR/S355JR Square Steel Tube |
| Product Type | Welded Square Steel Tube |
| Steel Grade | S235JR, S355JR, SS400, Q235B, A36 |
| Standard | EN 10219, EN 10210, ASTM A500, JIS G3466, GB/T 6728 |
| Section Shape | Square |
| Size Range | Customized |
| Wall Thickness | Customized |
| Length | 6m / 8m / 12m or Customized |
| Technique | ERW (Electric Resistance Welded) / Cold Rolled |
| Surface Treatment | Cold Rolled / Galvanized (optional) |
| Tolerance | ±1% |
| Ends | Plain |
| Invoicing | By Theoretical Weight |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Application | Building structures, machinery manufacturing, infrastructure, vehicle manufacturing, furniture |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Architecture | Exposed steel frameworks, stadium roof trusses, commercial center columns, curtain wall supports |
| Machinery Manufacturing | Automation equipment frames, conveyor support structures, crane booms, machine bases |
| Infrastructure | Bridge auxiliary structures, stage trusses, solar panel mounting frames, greenhouse skeletons |
| Vehicle Manufacturing | Trailer chassis frames, cargo bed supports, structural reinforcements |
| Furniture & Interior | Industrial-style shelving, decorative structural elements, display rack frames |
Where EN 10219 Certification Decides Customs Clearance for S355JR ERW Square Steel Tube
A missing or incorrect CE mark under EN 10219 can halt an entire container at EU customs — regardless of how well the tubes are manufactured.
Importers across Europe have reported shipments held at port because the mill test certificate referenced the wrong standard clause, or the CE declaration cited EN 10210 instead of EN 10219 for cold-formed welded sections. The physical product may be identical, but the paperwork mismatch triggers rejection under the EU Construction Products Regulation. When sourcing S355JR ERW square steel tube for structural applications, confirming that the manufacturer holds valid CE certification specifically for EN 10219 is not optional — it determines whether your goods clear customs or sit in a bonded warehouse for weeks. [NEED_CITE: EN 10219 cold-formed welded hollow section CE marking requirements]
Matching S355JR ERW Square Steel Tube to Structural Load Requirements
S355JR ERW square steel tube delivers the yield strength range that structural engineers specify for medium-to-heavy load-bearing frameworks in commercial buildings and industrial facilities. The cold-rolled ERW process produces consistent wall thickness and smooth surface finish, which matters when tubes are left exposed in architectural applications — no additional grinding is needed before painting or powder coating. Our in-house laboratory tests every heat for chemical composition and dimensional accuracy before release, so the S355JR tubes you receive match the mill test certificate attached to your shipment. For projects requiring S235JR instead, we produce both grades on the same ERW lines with full EN 10219 compliance.
Engineering Compliance and Standard Alignment for Welded Square Tubes
Structural design codes such as EN 1993 (Eurocode 3) and AISC 360 reference specific material standards for hollow structural sections. S355JR under EN 10219 meets the requirements for non-alloy structural steel in welded square hollow sections, while the equivalent ASTM A500 Grade C serves North American projects. When your project specification calls for EN 10219, the manufacturer must provide CE certification under that exact standard — not EN 10210, which covers hot-finished seamless sections. Our facility holds CE certification for both EN 10210 and EN 10219, and we mark each bundle with the correct standard reference to avoid customs complications. [NEED_CITE: steel grade equivalence between EN 10219 and ASTM A500 standards]
Understanding S355JR Steel Grade and ERW Welding Process
S355JR belongs to the European non-alloy structural steel family, where the “355” indicates the minimum yield strength at 16mm thickness in MPa. Compared to S235JR, S355JR offers higher load-bearing capacity for the same cross-section, allowing engineers to reduce tube dimensions while maintaining structural performance. The ERW (Electric Resistance Welded) process forms the square profile from steel strip through cold forming, then welds the seam using electrical resistance heat — no filler metal is added. This produces a clean, consistent weld line that passes the flattening and bending tests required by EN 10219. Cold rolling after welding further improves dimensional accuracy to ±1% tolerance and delivers a smooth surface suitable for direct painting or galvanizing. For projects in corrosive environments, we offer hot-dip galvanized S355JR ERW square steel tube with zinc coating applied after forming.
Hidden Costs When Welded Square Tube Specifications Are Not Verified
Ordering S355JR ERW square steel tube without verified mill test certificates creates risk at three points: customs clearance, on-site inspection, and structural safety. If the certificate references the wrong standard or omits chemical composition data, EU customs will hold the shipment — and demurrage charges accumulate daily. On-site, if wall thickness falls outside the ±1% tolerance specified in EN 10219, the project engineer may reject the entire batch, forcing re-procurement and schedule delays. At the structural level, material that does not meet the specified grade can compromise load calculations, particularly in seismic zones or heavy-load industrial frames. [NEED_CITE: structural hollow section dimensional tolerance requirements under EN 10219]
Why Source S355JR ERW Square Steel Tube from Our Jinan Facility
We manufacture S355JR and S235JR ERW square steel tube directly at our Jinan production base — no trading company margin, no third-party warehousing. Our facility covers over 2,800 specifications in square and rectangular hollow sections, with wall thicknesses up to 40mm, so custom non-standard sizes do not require sourcing from multiple suppliers. We hold 41 invention patents including China’s original sharp-corner rectangular tube technology, and we participated in drafting China’s cold-formed steel industry standards in 2018. Every shipment includes mill test certificates from our in-house physical and chemical laboratory, and we arrange SGS or BV third-party inspection before loading if your project requires it. Our CE certification under EN 10219 and EN 10210 covers EU market entry, and we handle professional container loading with anti-damage measures to prevent bending or surface scratches during ocean transit.
Documentation & Compliance
- Mill test certificate documenting S355JR and S235JR chemical composition and mechanical properties per EN 10219, including yield strength, tensile strength, and elongation values
- CE certificate covering EN 10219 cold-formed welded hollow sections and EN 10210 hot-finished sections, required for EU customs clearance
- ISO 9001:2015 quality management system certificate covering production, inspection, and traceability processes
- SGS or BV third-party inspection report available upon request, covering dimensional checks, visual inspection, and witness testing
- Heat number traceability on each bundle, linking physical tubes to specific mill test certificates and chemical analysis records
- Complete export documentation including commercial invoice, packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- S355JR and S235JR ERW square steel tubes packed in seaworthy steel strip bundles, with edge protectors to prevent coating damage during transit
- Galvanized tubes receive additional plastic wrapping at bundle ends to preserve zinc coating integrity during ocean shipping
- Container loading optimized for 6m, 8m, and 12m lengths to maximize payload per 20ft or 40ft container, reducing freight cost per ton
- Custom cut-to-length service available for 12m tubes, with cut ends deburred and marked with heat number and steel grade
- Each bundle labeled with steel grade (S355JR or S235JR), size, length, heat number, and EN 10219 standard reference
- Shipping terms available as FOB Qingdao, CIF destination port, or DDP door-to-door for project sites
Getting Your S355JR ERW Square Steel Tube Quote Started
Send us your required dimensions (outer size, wall thickness, length), steel grade (S235JR or S355JR), surface treatment preference, and destination port. We respond within 12 hours with pricing, lead time, and available mill test certificate samples. For non-standard sizes or custom lengths outside 6m/8m/12m, we provide production drawings and confirm tolerance compliance before you place the order.
Frequently Asked Questions
Q: What is the difference between S235JR and S355JR for ERW square steel tube applications?
A: S355JR offers higher minimum yield strength than S235JR, allowing engineers to specify smaller cross-sections for the same load requirement. Both grades are produced to EN 10219 and available in our ERW square tube range with full mill test certificates.
Q: Can you provide third-party inspection before shipment?
A: Yes, we arrange SGS or BV inspection at our facility before loading. The inspection covers dimensional verification, visual quality checks, and witness testing as required by your project specification.
Q: Do you hold CE certification for EN 10219?
A: Yes, our facility holds CE certification under both EN 10219 for cold-formed welded hollow sections and EN 10210 for hot-finished sections. This certification is required for EU market entry and customs clearance.
Q: What surface treatment options are available for S355JR ERW square steel tube?
A: We offer black (as-welded and cold-rolled), hot-dip galvanized, and painted finishes. Galvanized tubes are suitable for outdoor or corrosive environments, while black tubes are typically painted or powder-coated for architectural applications.
Q: What is the minimum order quantity for custom non-standard sizes?
A: Custom sizes outside our standard range are available with flexible MOQ depending on dimensions and quantity. Contact us with your specifications for a detailed production quote.
Get Your S355JR ERW Square Steel Tube Quote with Mill Test Certificates
Submit your dimensions, steel grade, and destination to receive pricing and compliance documentation within 12 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjypipe.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
