Description
Factory-direct stainless tube supply — vertically integrated mill and fabrication under one quality system from coil to finished welded tube.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | 201/304/316/316L Stainless Steel Square and Rectangular Welded Tube |
| Product Type | Welded Square and Rectangular Stainless Steel Tube (SHS/RHS) |
| Steel Grade | 201, 304, 301L, 305, 309S, 316, 316L, 316Ti, 410, 430, 439, 441 |
| Standard | ASTM A554 / GB |
| Section Shape | Square / Rectangular / Round / Oval |
| Size Range | Customized outer diameter or side length per request |
| Wall Thickness | 0.3–2.0 mm |
| Length | 5.8 m / 6.0 m / 6.1 m or customized (1–12 m available) |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | BA / 2B / No.3 / No.4 / HL / 6K / 8K (Mirror) |
| Tolerance | Outer diameter ±0.2 mm / Thickness ±0.03 mm / Length ±10 mm |
| Ends | Plain |
| Application | Decorations / Handrails / Railings / Window / Balcony / Curtain Wall / Furniture / Construction Structure |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Architectural Decoration | Handrails, railings, balcony balustrades, elevator interior trim, curtain wall framing |
| Commercial Furniture | Structural frames for retail displays, restaurant seating, shelving supports |
| Building Construction | Window frames, light-duty structural supports, door thresholds |
| Interior Fit-out | Decorative partition tubing, ceiling grid supports, wall-mounted fixtures |
When Wall-Thickness Tolerance Decides Whether Your Handrail Passes Inspection
A ±0.03 mm thickness tolerance on a 0.5 mm wall is the difference between a clean site acceptance and a full batch rejection.
Sourcing 201 304 316L stainless steel square rectangular tube supplier from fragmented vendors means each batch carries its own tolerance story. I have seen decorative handrail tubes arrive at a Middle East project site where the wall thickness drifted into negative territory past the acceptable limit — the third-party inspector flagged the entire container, and the contractor faced a two-week delay while replacement material was air-shipped. The root cause was never the steel grade itself; it was the absence of a single accountable source controlling both the coil and the forming process. When material procurement and tube fabrication sit under one roof, the tolerance chain shortens, and the mill test certificate actually reflects what arrives on the truck. [NEED_CITE: ASTM A554 decorative stainless steel tube tolerance requirements]
Matching Surface Finish to the Corrosion Environment of Your Project Site
Architectural handrails and balcony balustrades in coastal cities demand more than a decorative look — the surface finish directly determines how long the tube resists salt spray before staining appears. A 201 304 316L stainless steel square rectangular tube supplier running a full finish range from 2B industrial to 8K mirror lets you specify No.4 brushed for interior elevator trim where fingerprints matter less, and 6K or 8K mirror for lobby feature walls where reflectivity is the design intent. For exterior railing systems in humid subtropical climates, 316L with a HL or No.4 finish provides molybdenum-enhanced pitting resistance without sacrificing the brushed aesthetic architects typically call for. The key is matching the finish specification to both the environment and the maintenance schedule the building owner will actually follow.
Engineering Compliance and Grade Selection for Structural versus Decorative Use
Load-bearing window frames and light structural supports require verified chemical composition and mechanical properties that conform to ASTM A554, with mill test certificates traceable by heat number. Decorative applications such as curtain wall trim or furniture frames prioritize surface consistency and weld line quality over structural certification, yet buyers still need documentation proving the grade matches the purchase order. For projects entering the European market, confirming grade equivalence between ASTM and EN designations avoids customs holds at the port of entry [NEED_CITE: stainless steel grade equivalence between ASTM and EN standards]. Custom lengths from 1 to 12 meters reduce on-site cutting waste, and plain ends allow field welding or mechanical connection without secondary preparation.
Understanding ERW Weld Quality and Grade Coverage in Stainless Welded Tubes
The ERW welding process forms the tube by rolling stainless steel strip into shape and fusing the seam through electric resistance — no filler metal is added, which means the weld zone chemistry matches the base material. This matters for 316L tubes used in corrosive environments: a poorly controlled ERW seam can become the weak point where chromium depletion occurs during welding, reducing local corrosion resistance. Our integrated mill controls the strip chemistry from the melt shop through the forming line, so the 316L weld seam carries the same molybdenum content as the parent metal. The grade range spans austenitic 201, 304, 316L and ferritic 430, 439, 441 — covering everything from budget-conscious interior decoration to marine-grade exterior installations. Wall thickness from 0.3 to 2.0 mm accommodates both thin-gauge decorative tubing and heavier structural profiles, with the ±0.03 mm thickness tolerance holding across the full range.
The Hidden Cost of Accepting Unverified Tolerances on Decorative Tube Orders
Ordering stainless tubes based on price alone, without confirmed mill test certificates or third-party inspection, invites problems that surface long after the invoice is paid. Material that fails to match the specified grade — 201 substituted for 304, or 304 sold as 316L — will show rust stains within months in coastal or industrial environments, triggering warranty claims and replacement costs that dwarf the original purchase savings. Missing or forged certificates create customs clearance failures, particularly in markets requiring EN 10204 3.1 documentation for architectural steel products [NEED_CITE: EN 10204 inspection certificate types for steel products]. Negative tolerance abuse on wall thickness reduces both the structural capacity and the perceived quality of finished handrails, where a visibly thin wall signals cheap procurement to the building owner.
Why Project Procurement Teams Consolidate Stainless Tube Orders With Us
Our Shandong facility operates its own steel production lines alongside the tube fabrication workshop, meaning the coil that enters the slitting line and the finished 201 304 316L stainless steel square rectangular tube supplier shipment share one material traceability chain. The in-house理化 laboratory issues mill test certificates for every heat number, documenting chemical composition and confirming grade compliance before the tubes leave the facility. With over 2,800 specifications in our raw material inventory, non-standard dimensions and mixed-size orders ship from a single warehouse rather than requiring coordination across multiple subcontractors. Professional loading teams handle the surface protection requirements of polished and mirror-finish tubes, using separators and edge protectors that prevent transit scratching on BA, No.4, and 8K surfaces. Third-party inspection through SGS, BV, or TÜV is coordinated on-site before container sealing, so the inspection report reflects the actual shipment rather than a pre-shipment sample.
Documentation & Compliance
- Mill test certificate (EN 10204 3.1 format) documenting 201, 304, or 316L chemical composition including carbon, chromium, nickel, and molybdenum content per heat number
- ASTM A554 compliance certificate confirming mechanical properties and tolerance conformance for the specific grade and dimension ordered
- ISO 9001 quality management certificate covering the integrated steel production and tube fabrication process
- SGS / BV / TÜV third-party inspection report covering dimensional verification, surface finish grading, and weld seam quality for the shipped batch
- Full material traceability from steel coil heat number through slitting, forming, welding, and final inspection records
- Export documentation package including commercial invoice, packing list, bill of lading, and certificate of origin for customs clearance
Packaging, Loading & Delivery
- BA and 8K mirror finish tubes packed with individual paper interleaving and foam separators inside seaworthy steel strip bundles to prevent surface contact damage during ocean transit
- 5.8 m and 6.0 m standard lengths loaded in 20-foot containers with wooden cradles at quarter-points to prevent bowing; 6.1 m lengths optimized for 40-foot high-cube containers
- Custom cut lengths between 1 and 12 m bundled separately with heat number and grade stenciled on each bundle tag for site identification
- 201 and 304 tubes with 2B or No.4 finish coated with protective film on request for projects requiring extended storage before installation
- FOB Qingdao port as standard, with CIF and DDP arrangements available to major destination ports based on order volume
- Container loading supervised with photographic records provided before seal application, documenting bundle count and securing method
Starting Your Procurement With Drawings and Grade Requirements
Share your project drawings in PDF or DWG format along with the specified stainless steel grade, surface finish, dimensions, and total quantity — our engineering team responds within 24 hours with a preliminary assessment and quotation covering material, fabrication, surface treatment, packing, and shipping costs. For projects requiring ASTM A554 compliance documentation or third-party inspection coordination, confirm these requirements at the inquiry stage so the quality plan is built into the production schedule from the start.
Request a Quotation With Mill Test Certificates
Send your specifications, grade requirements, and destination port to receive a detailed quotation with full quality documentation.
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
