Description
Factory-direct stainless square tubes — Vertically integrated from raw stainless steel coil to finished welded square profiles, eliminating third-party material sourcing gaps.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | 304 Stainless Steel Welded Square Steel Tube |
| Product Type | Welded Square Steel Tube (Stainless Steel) |
| Steel Grade | 304, 201 |
| Standard | AISI, ASTM, BS, DIN, GB, JIS, EN |
| Section Shape | Square |
| Size Range | 25×25 mm – 200×200 mm |
| Wall Thickness | 1 – 10 mm |
| Length | 1000 – 6000 mm |
| Technique | Cold Rolled / Hot Rolled, Welded (Seamless-ERW) |
| Surface Treatment | BA / 2B / NO.1 / NO.3 / NO.4 / 8K / HL / 2D / 1D |
| Tolerance | ±1% |
| Ends | Plain Ends / Cut-to-Length |
| Application | Construction, Building, Industry, Structural Frames, Machinery, Furniture |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Building | Structural frames, curtain wall supports, handrail systems, canopy structures |
| Industrial & Machinery | Equipment enclosures, conveyor frame structures, machine guards, platform supports |
| Architectural & Decorative | Interior column cladding, decorative screen frames, furniture structural components |
| Infrastructure | Walkway supports, signage structures, utility enclosure frames |
Material Certification Gaps That Trigger Customs Rejection
Forged mill certificates on stainless steel square tubes lead to container-level rejection at destination port.
Sourcing a 304 stainless steel welded square tube supplier overseas often means trusting a trading company’s paperwork rather than verified chemistry. When 201 grade material ships with 304 documentation, third-party inspection at the discharge port catches the nickel content discrepancy — the entire shipment gets held, re-tested, and often rejected. The buyer absorbs air-freight replacement costs, project delays, and potential structural liability if non-conforming material was already installed. [NEED_CITE: stainless steel grade verification methods for import inspection]
Precision Tolerance for Structural Frame Assembly
A 304 stainless steel welded square tube supplier controlling ±1% wall thickness tolerance ensures that bolt-hole alignment and connection plate fit-up proceed without on-site rework. When structural frames for industrial facilities require multiple welded square tubes to mate at precise angles, even 0.5 mm deviation on a 200×200 mm profile compounds across connection nodes. Our integrated production from raw coil to finished square tube maintains dimensional consistency across the full 25×25 to 200×200 mm range, verified through in-process dimensional checks at every production stage.
Engineering Compliance for Corrosive Environments
Stainless steel square tubes in 304 grade serve architectural and industrial applications where corrosion resistance matters — coastal construction, food processing facilities, and chemical plant support structures. The chromium-nickel composition of 304 provides oxidation resistance superior to 201 grade, though 201 remains suitable for interior decorative applications where exposure is limited. For projects requiring EN or ASTM compliance documentation, material traceability by heat number and certified Mill Test Certificates become mandatory for customs clearance and engineering approval. [NEED_CITE: 304 vs 201 stainless steel corrosion resistance comparison]
Welded ERW Process and Surface Finish Selection
The ERW welding process for stainless steel square tubes produces a continuous longitudinal seam that, after proper heat treatment and weld bead removal, maintains corrosion resistance comparable to the parent material. Surface finish options — BA (bright annealed), 2B (cold rolled), NO.4 (brushed), 8K (mirror) — serve different functional requirements: BA and 2B for industrial machinery where appearance is secondary, NO.4 and 8K for architectural applications where visual finish matters. The choice between cold rolled and hot rolled technique affects both surface quality and cost, with cold rolled providing tighter dimensional tolerance for precision structural applications.
Hidden Costs of Unverified Stainless Steel Procurement
Purchasing stainless steel square tubes without verified material certification creates downstream costs that dwarf initial price savings. When 201 grade material — with lower nickel content and reduced corrosion resistance — enters a project specified for 304, the consequences include failed third-party inspection, structural engineer rejection, and potential replacement of installed components. Engineering standards require documented proof of material compliance; without heat-number traceable Mill Test Certificates, project acceptance becomes impossible regardless of actual material quality. [NEED_CITE: material traceability requirements for structural stainless steel]
Integrated Production Control from Coil to Finished Tube
Our vertically integrated facility produces stainless steel square tubes from raw coil through finished welded profiles, maintaining material traceability throughout the production chain. Every heat number from the steel mill follows through to the finished tube’s certification documentation, eliminating the documentation gaps that occur when fabricators source raw material from third parties. The 2800+ specification range covers the full 25×25 to 200×200 mm size spectrum in both 304 and 201 grades, with in-house cutting, punching, and welding services reducing the need for secondary processing at destination. Certified welding procedures and qualified welders ensure that any fabrication work maintains the corrosion resistance and structural integrity of the base material.
Documentation & Compliance
- Mill Test Certificate documenting 304 stainless steel chemical composition (Cr, Ni, C content) and mechanical properties per ASTM A240 or EN 10088 standards
- CE certificate confirming compliance with EN 10219 cold-formed welded structural hollow section requirements for European market projects
- ISO 9001 quality management system certification covering the full production process from raw material inspection through finished tube testing
- SGS or BV third-party inspection report available for pre-shipment verification of dimensions, surface finish, and material grade
- Material traceability documentation linking each bundle to specific heat numbers with corresponding chemistry test results
- Export customs documentation including packing list, bill of lading, and certificate of origin for destination port clearance
Packaging, Loading & Delivery
- Stainless steel square tubes bundled with steel strips and edge protectors to preserve BA/NO.4/8K surface finish during ocean transit
- Cut-to-length service available for 1000-6000 mm lengths, reducing on-site cutting waste and optimizing container loading efficiency
- 200×200 mm square tubes loaded in dedicated container configurations maximizing weight utilization while preventing surface damage
- Heat number and steel grade markings applied to each bundle for site identification and inspection traceability
- FOB, CIF, and DDP shipping terms available with professional export packing suitable for long-distance ocean freight
- Professional loading plans for oversized square tube bundles ensuring weight distribution and securing during container transit
Project Inquiry and Quotation Process
Submit your project specifications including steel grade (304 or 201), dimensions (25×25 to 200×200 mm), wall thickness, surface finish requirement, and total quantity to receive a detailed quotation with Mill Test Certificate confirmation. For custom cut-to-length or processing requirements, share your fabrication drawings for engineering review and production feasibility assessment. Certification and customs documentation requirements should be confirmed at inquiry stage to ensure compliance with destination country import regulations.
Frequently Asked Questions
Q: What is the difference between 304 and 201 stainless steel for square tube applications?
A: 304 stainless steel contains higher nickel content (8-10.5%) providing superior corrosion resistance for outdoor and industrial environments, while 201 grade (1-5% nickel) suits interior decorative applications where cost optimization is priority. For coastal construction or chemical exposure, 304 grade is recommended.
Q: Can you provide Mill Test Certificates with heat number traceability?
A: Yes, every 304 stainless steel welded square tube ships with Mill Test Certificate documenting chemical composition and mechanical properties, with heat number traceability from raw material through finished product. Third-party inspection by SGS or BV is available for additional verification.
Q: What surface finishes are available for architectural applications?
A: We offer BA (bright annealed), NO.4 (brushed/satin), and 8K (mirror) finishes for architectural square tubes where visual appearance matters. Industrial applications typically use 2B or NO.1 finish for cost efficiency.
Q: Do you provide cut-to-length and fabrication services?
A: Yes, in-house processing includes cutting to specified lengths within the 1000-6000 mm range, punching, and welding services. Share your fabrication drawings for engineering review and production scheduling.
Q: What is the minimum order quantity for custom sizes?
A: The minimum order quantity is 1 Ton. For standard sizes in the 25×25 to 200×200 mm range, typical production lead times apply. Non-standard dimensions require engineering review for feasibility assessment.
Request Quotation with Material Certification
Submit your project specifications — steel grade, dimensions, surface finish, quantity, and destination port — to receive a detailed quotation including Mill Test Certificate confirmation and production schedule.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
