Description
Direct Mill Supply, No Broker Markup — S235JR and S355 square steel tubes produced from our own steel mill with full material traceability from slab to finished section.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S235JR/S355 Square Steel Tube |
| Product Type | Welded Square Steel Tube |
| Steel Grade | S235JR, A36, S355, SS400, Q235B |
| Standard | ASTM A500, EN10219, EN10210, JIS G3466, GB/T 6728 |
| Section Shape | Square |
| Outer Diameter or Side Length | Customized |
| Wall Thickness | Customized |
| Length | Customized |
| Technique | Cold Rolled / Welded |
| Surface Treatment | Cold Rolled (Galvanized available per customer requirement) |
| Tolerance | ±1% |
| Ends | Plain |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Application | Building structures, Machinery manufacturing, Infrastructure construction, Vehicle manufacturing |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Steel frame structures, columns and beams for warehouses, logistics centers, stadiums |
| Industrial Facilities | Machine tool frames, conveyor support frames, automation equipment bases, platform structures |
| Infrastructure | Auxiliary bridge structures, stage trusses, greenhouse frames, renewable energy support frames |
| Vehicle Manufacturing | Trailer chassis, RV frames, heavy transport subframes |
| Architectural & Decor | Stair handrails, security window frames, structural furniture frames |
What Negative Tolerance Actually Costs on a Structural Frame Order
A 0.4mm wall thickness deviation can turn a compliant shipment into a rejected container at the port.
Overseas buyers outsourcing square steel tube fabrication face persistent quality uncertainty—welding defects hidden under paint, dimensional inaccuracy causing fit-up failures on site, and missing material certifications that stall customs clearance. When a S355 square steel tube supplier delivers product outside the specified tolerance, the entire structural connection design becomes compromised. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]
Matching Structural Load Requirements for EPC Projects
Cold rolled S355 square steel tubes with ±1% tolerance ensure dimensional accuracy critical for bolted and welded structural connections in EPC projects. The consistent geometry allows predictable load distribution across frame joints, reducing on-site adjustment time. For warehouse and logistics center construction, our vertically integrated production eliminates material traceability gaps that plague fragmented procurement.
Engineering Compliance Across International Standards
S355 square steel tube production conforms to EN10219 for cold-formed welded hollow sections, meeting European structural steelwork execution requirements. [NEED_CITE: EN 1090 structural steel fabrication execution classes] ASTM A500 Grade B and C options serve North American projects requiring different yield strength classifications. CE marking documentation supports EU customs clearance, while mill test certificates accompany every heat for Middle East and African project inspections.
Steel Grade Selection and Cold Rolling Process
S235JR provides adequate strength for non-critical architectural applications, while S355 delivers higher yield strength for primary structural members in industrial buildings. The cold rolled process improves surface finish and dimensional consistency compared to hot-formed alternatives, producing sharp corners that enhance connection fit-up. [NEED_CITE: steel grade equivalence between EN S355JR and ASTM A500 Grade C] Q235B and SS400 serve projects specifying Chinese or Japanese standards respectively, with equivalent mechanical properties across the S-series and Q-series designations.
Hidden Costs of Unverified Material Sources
Purchasing from traders without mill-direct traceability invites material substitution risks—lower-grade steel shipped as S355, wall thickness below tolerance, or missing chemical composition data. [NEED_CITE: material certification requirements for structural steel in international construction] Projects face engineering rejection, customs detention, or worst case, structural safety concerns discovered during inspection. Complete documentation packages including WPS, PQR, and dimensional inspection reports prevent these costly delays.
Why Source S355 Square Steel Tube from XJY Structure
Our own steel mill operates 3 production lines with 2,800+ specifications in stock, eliminating the gap between material supplier and fabricator. Every S355 square steel tube carries full traceability from raw slab through cold rolling and welding, with certified welders working to approved WPS procedures. We provide shop drawing review, material optimization, and complete quality documentation—WPS, PQR, weld maps, dimensional inspection reports, and coating reports—ready for international project submission. Third-party inspection through SGS or BV available for projects requiring independent verification.
Documentation & Compliance
- Mill test certificate documenting S355JR chemical composition and yield strength per EN10219, with heat number traceability
- CE certificate confirming EN10219 compliance for cold-formed welded square hollow sections
- ISO 9001 quality management certificate covering fabrication and inspection processes
- SGS or BV third-party inspection report available for projects requiring independent verification
- Material traceability documentation linking each tube to specific heat numbers and production records
- Complete export documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- S355 square steel tubes bundled with steel strips and edge protectors to preserve cold rolled surface finish during ocean transit
- Custom length cutting service available to match project specifications, reducing on-site waste
- Galvanized coating protection measures applied when surface treatment specified, preventing transport damage
- Professional loading plans optimized for container utilization based on customized dimensions and wall thickness
- Heat number and steel grade marking on each bundle for site identification and inspection traceability
- FOB, CIF, and DDP terms available with professional oversized cargo loading for large section sizes
Getting Your S355 Square Steel Tube Quote
Share your project drawings with specifications, steel grades, required standards, and quantities to receive a detailed quotation within 24 hours. Our engineering team reviews shop drawings and provides material optimization recommendations before production begins. Confirm certification requirements and destination port to ensure complete documentation package for customs clearance.
Frequently Asked Questions
Q: Can you provide material certificates for S355 square steel tube meeting EN10219?
A: Yes, every shipment includes mill test certificates documenting chemical composition and mechanical properties per EN10219, with heat number traceability from raw material to finished product.
Q: What is the tolerance on wall thickness for cold rolled square tubes?
A: Our cold rolled S355 square steel tubes maintain ±1% tolerance on wall thickness, verified through dimensional inspection reports included in the quality documentation package.
Q: Do you offer custom lengths and cutting services?
A: Yes, we provide cutting to custom lengths per project specifications, along with additional processing services including welding, punching, bending, and decoiling.
Q: Can you arrange third-party inspection for our project?
A: Third-party inspection through SGS or BV is available for projects requiring independent verification of material properties and dimensional accuracy.
Q: What surface treatment options are available?
A: Cold rolled finish is standard, with hot-dip galvanized or painted options available per customer requirement and project specifications.
Request Your S355 Square Steel Tube Quotation
Submit your project specifications, steel grade requirements, and destination port to receive a detailed quotation with mill test certificate confirmation.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
