Description
Direct Mill Supply for ASTM A312 Stainless Tubes — XJY Structure produces raw stainless steel and fabricates finished square and rectangular welded tubes in-house, covering grades from 201 to 904L with BA surface finish.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | 304/304L/316/316L/321/201 Stainless Steel Square and Rectangular Welded Steel Tube |
| Product Type | Square and Rectangular Welded Stainless Steel Tube (SHS/RHS) |
| Steel Grade | 201, 301, 301L, 304, 304L, 304N, 304H, 310S, 316, 316L, 317, 321, 410, 904L |
| Standard | ASTM A312 |
| Section Shape | Square / Rectangular |
| Size Range (Side Length) | 5 mm – 400 mm |
| Technique | Cold Rolled / ERW (Welded) |
| Surface Finish | BA (Bright Annealed) |
| Tolerance | ±5% |
| Welding Line Type | ERW |
| Invoicing | By Actual Weight |
| Delivery Time | 15–21 days |
| MOQ | 1 Ton |
| Payment Terms | L/C, T/T (30% Deposit) |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Architectural & Decorative | Curtain wall frames, handrail structures, interior column cladding, elevator shaft frameworks |
| Food & Pharmaceutical Processing | Hygienic piping supports, cleanroom structural frames, equipment skids requiring easy-clean surfaces |
| Chemical & Petrochemical | Pipe racks, cable tray supports, ducting frameworks in chloride-exposed environments |
| Gas Distribution Systems | Indoor and outdoor gas line structural supports, metering station frames |
Why Material Traceability Decides Whether Your Stainless Tubes Pass Port Inspection
When the mill certificate says 316L but the spectrometer reads 304L chemistry, the entire container goes back.
I once shipped a full container of stainless square tubes to a Middle East project. The paperwork declared 316L across every piece. When the client ran handheld XRF at the port, nickel content came back far below 316L minimums — the batch had been mixed with 304L during production. The whole shipment was rejected. Since then, every stainless tube leaving our facility goes through spectrometer verification before packing, and because we produce the raw material in our own steel mill, there is no third-party sourcing gap where grade substitution can hide. For buyers sourcing a 304 316L stainless steel square rectangular tube supplier, this traceability chain from melt to finished tube is the single most important factor in avoiding customs rejection and on-site rework. [NEED_CITE: material traceability requirements for stainless steel in ASTM A312]
Matching Stainless Grades to Corrosive and Structural Environments
A 304 316L stainless steel square rectangular tube supplier must help you choose correctly between grades — because the cost difference between 304 and 316L is significant, and the performance gap in chloride environments is even larger. For indoor architectural frames in dry climates, 304 with BA finish delivers the aesthetic surface without the 316L premium. For coastal structures, chemical plant pipe racks, or outdoor gas systems exposed to salt spray, 316L’s molybdenum content provides pitting resistance that 304 simply cannot match. Our vertically integrated production means we stock both grades simultaneously and can ship mixed-grade orders from a single purchase order — one quality system, one set of mill certificates, one point of accountability.
Engineering Compliance and Certification Pathways
ASTM A312 governs the chemical composition, mechanical properties, and manufacturing practices for welded austenitic stainless steel tubes. For projects in the European market, cross-referencing to EN 10217-7 may be required, and the BA surface finish on our cold-rolled ERW tubes eliminates the need for secondary polishing — reducing both cost and lead time. Dimensional tolerance of ±5% on side lengths from 5 mm to 400mm covers both precision instrumentation frames and heavier structural applications. Third-party inspection through SGS, BV, or TÜV can be arranged before shipment to satisfy project-specific QA requirements. [NEED_CITE: ASTM A312 welded austenitic stainless steel pipe and tube requirements]
Cold-Rolled ERW Process and BA Surface Finish Explained
Our stainless square and rectangular tubes are produced through cold rolling followed by ERW (Electric Resistance Welding), then finished with Bright Annealing. The cold-rolling step ensures tight dimensional control and smooth surface geometry — critical for architectural applications where visible weld lines or surface irregularities are unacceptable. BA finish is achieved by annealing in a controlled-atmosphere furnace, which preserves the reflective surface without mechanical polishing. This matters for hygienic environments in food processing and pharmaceutical facilities, where surface roughness directly affects bacterial adhesion and cleanability. The ERW weld seam is fully fused and can be made virtually invisible after BA treatment — an advantage over hot-finished alternatives for decorative and sanitary applications. Grade coverage spans from economical 201 through high-performance 904L, allowing a single PO to address corrosion-resistant, high-temperature, and hygienic requirements simultaneously.
Hidden Costs of Buying Stainless Tubes Without Verified Grade and Finish
Ordering stainless tubes based on price alone carries risks that surface only at the project site. A tube labeled 316L with insufficient molybdenum will show pitting corrosion within months in a coastal environment — but by then, the structure is already installed and replacement means demolishing adjacent work. Missing or incomplete mill certificates cause customs holds at destination ports, particularly in the EU and Middle East where EN 10204 3.1 documentation is routinely demanded. Oversized tolerance deviations create fit-up problems during assembly, forcing on-site cutting and re-welding that delays the schedule and introduces uncontrolled weld zones. [NEED_CITE: EN 10204 inspection document types for steel products]
Why Buyers Choose XJY Structure as Their Stainless Tube Source
We operate our own steel production facility with multiple production lines and over 2,800 raw material specifications in stock — meaning the stainless steel strip that becomes your square or rectangular tube never passes through a third-party trader. Our in-house理化实验室 performs spectrometer analysis on every heat, and we issue full Mill Test Certificates with chemical composition traceable to heat numbers. For stainless grades specifically, we maintain dedicated production protocols to prevent cross-contamination between 304-series and 316-series runs — a lesson learned the hard way from that Middle East rejection years ago. Custom cut-to-length, non-standard dimensions, and mixed-grade container loading are handled from a single facility, eliminating the coordination gaps that arise when material sourcing and fabrication are split between different vendors.
Documentation & Compliance
- Mill Test Certificate (EN 10204 3.1) documenting full chemical composition including Ni, Cr, Mo content per ASTM A312 for each heat number
- Third-party inspection reports from SGS, BV, or TÜV covering dimensional checks, surface finish verification, and weld integrity
- Material traceability sheet linking every finished tube to its original heat number and raw material test results
- Complete export documentation package: commercial invoice, packing list, bill of lading, and certificate of origin
- Welding procedure records (WPS/PQR) for ERW process parameters specific to each stainless grade produced
Packaging, Loading & Delivery
- BA-finish stainless tubes wrapped in protective film and bundled with non-metallic straps to prevent surface scratching during ocean transit
- Edge protectors applied to all square and rectangular tube bundles to preserve corner geometry and BA surface at sharp edges
- Container loading optimized by our team based on tube dimensions (5–400mm side lengths) and cut lengths to maximize payload per 20ft or 40ft container
- Heat number and grade markings stenciled on each bundle for on-site identification and traceability verification
- FOB, CIF, and DDP shipping terms available with full export documentation and real-time tracking until site delivery
Start Your Procurement with Drawings and Grade Requirements
Share your project drawings (PDF/DWG), required stainless grades, dimensions, surface finish preferences, and destination port — our engineering team responds within 24 hours with a detailed quotation including material costs, fabrication charges, documentation packages, and shipping estimates. For projects requiring mixed grades or custom dimensions outside standard ranges, we provide shop drawing reviews and material optimization recommendations before contract signing.
Request Your ASTM A312 Stainless Tube Quotation Today
Send your specifications, steel grades, and quantities to receive pricing with full mill test certificates and third-party inspection options.
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
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
