Description
Factory-Direct Stainless Steel Tube Supplier — 201, 304, 316L, and 316Ti ERW welded square and rectangular tubes produced in-house with BA bright annealed surface, shipped directly from Jinan to 50+ countries without trading intermediaries.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | 300 Series Stainless Steel Welded Square and Rectangular Tube |
| Product Type | Welded Square and Rectangular Steel Tube (Stainless Steel) |
| Steel Grade | 201, 304, 316, 316L, 316Ti, 430, 439 |
| Standard | GB |
| Section Shape | Square / Rectangular |
| Size Range | 10mm × 20mm – 100mm × 200mm |
| Wall Thickness | 0.8mm – 5.0mm |
| Length | 1m / 2m / 3m / 6m |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | BA (Bright Annealed) / Mirror Polish / Brushed / Satin / Matt |
| Tolerance | ±1% |
| Ends | Plain / Cut to order |
| Application | Decorations, handrails, railings, stair balustrades, balcony balustrades, window frames, door frames, kitchen equipment, display racks, furniture frames, architectural trim |
| MOQ | Negotiable |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Architectural Facades & Curtain Walls | Glass curtain wall framing, facade trim profiles, decorative cladding supports |
| Handrail & Balustrade Systems | Stair handrails, balcony railings, guardrails for commercial and residential buildings |
| Interior Fit-Out & Furniture | Commercial furniture frames, retail display racks, kitchen equipment structures |
| Door & Window Manufacturing | Window frames, door frames, architectural trim for high-end residential and office projects |
Surface Defects on BA Finish Tubes Cost More Than the Material Itself
A scratched BA surface means the entire batch fails visual inspection on site.
When architects specify bright annealed stainless steel for handrails or curtain wall trim, they expect a mirror-consistent finish straight out of the tube — no grinding, no re-polishing. I once saw a container of 304 square tubes arrive at a Lagos commercial complex with the BA surface scored from improper stacking separators. The contractor rejected the full shipment. The corner R-angle also exceeded the drawing tolerance, making the miter joints gape. That single oversight — wrong separator material and no per-piece angle check — wiped out months of procurement planning. Surface quality uncertainty, inconsistent corner geometry, and missing material traceability remain the top reasons decorative stainless tube orders get rejected at destination [NEED_CITE: stainless steel surface finish standards for architectural applications].
Matching Finish and Grade to the Corrosion Environment
Selecting the right 304 316L stainless steel square rectangular tube supplier starts with matching the steel grade to the actual exposure condition. For indoor handrails and furniture frames in dry environments, 201 offers acceptable corrosion resistance at lower cost. For outdoor balustrades and facade trim in urban settings, 304 provides reliable passivation layer performance. In coastal or high-humidity regions, 316L and 316Ti resist chloride-induced pitting that would degrade 304 within months. The ERW welding process with ±1% dimensional tolerance ensures that cut pieces fit together without visible gaps at welded joints — critical for continuous handrail runs and curtain wall mullion connections. Our in-house laboratory verifies chemical composition per batch, confirming molybdenum content in 316L grades before dispatch.
Engineering Compliance and Certification Requirements
Architectural stainless steel tubes used in structural handrails and balustrade systems must comply with load-bearing codes such as EN 1993-1-4 for stainless steel structures or local building regulations governing guardrail lateral force resistance [NEED_CITE: stainless steel structural design codes for handrail and balustrade systems]. The GB standard governs production tolerances, but projects in the EU require CE marking under EN 10219 for cold-formed welded structural hollow sections. Surface finish selection — BA bright annealed for high-visibility interiors, brushed or satin for fingerprint-resistant exterior handrails — must be locked before production, as post-production re-finishing introduces cost and consistency risk. Custom lengths of 1m to 6m reduce on-site welding and preserve the factory-applied finish. Third-party inspection by SGS or BV confirms dimensional accuracy and surface quality before container sealing.
Understanding ERW Welding and Stainless Steel Grade Selection
ERW (Electric Resistance Welded) welding joins the rolled strip edges through localized heat and pressure without filler metal, producing a clean weld line suitable for decorative applications where the weld seam is minimal or hidden. This process suits the 0.8mm–5.0mm wall thickness range of these tubes, balancing formability with structural rigidity. The 200-series grades (201) use manganese-nitrogen substitution for partial nickel replacement, reducing cost but limiting corrosion resistance compared to 300-series austenitic grades. 304 remains the baseline architectural grade with 18% chromium and 8% nickel. 316L adds 2–3% molybdenum for chloride resistance, while 316Ti incorporates titanium to prevent chromium carbide precipitation during welding — essential for tubes that will undergo on-site welding without post-weld annealing. The 400-series ferritic grades (430, 439) offer magnetic properties and lower cost for indoor decorative trim where high corrosion resistance is not required. Wall thickness tolerance of ±1% ensures consistent weight and load capacity across the full order.
Hidden Costs of Specifying the Wrong Grade or Finish
Ordering 201 grade for a coastal balcony railing instead of 316L leads to visible rust staining within a single rainy season — replacement cost far exceeds the original material savings. Specifying mirror polish when the design calls for brushed satin creates fingerprint magnetism and glare complaints from building occupants. Missing CE documentation blocks customs clearance at EU ports, triggering demurrage charges and project delays [NEED_CITE: CE marking requirements for steel hollow sections in European construction]. Tubes produced without verified heat-number traceability cannot pass structural audit requirements, forcing the contractor to source replacement material at spot-market prices. These failures are preventable with proper grade-environment matching, certified surface finish control, and complete mill documentation.
Procurement Confidence from a Specialist Stainless Tube Mill
As the original inventor of sharp-corner rectangular steel tubes in China with 41 invention patents, Shandong Xin Jiyuan operates dedicated production lines covering 2,800+ specifications — including this full range of ERW welded stainless steel square and rectangular tubes. Our in-house physical and chemical laboratory tests every heat for composition, tensile properties, and dimensional accuracy before release. Full international certifications — ISO 9001:2015, Lloyd’s CE (EN 10210/10219), Singapore FPC, and SGS/BV verification — ensure smooth customs clearance across 50+ export destinations. We produce custom non-standard sizes with low MOQ, and our professional container loading team uses separated padding and surface protection protocols developed from years of architectural project supply — the same protocols that prevent the BA surface damage I witnessed on that Lagos job.
Documentation & Compliance
- Mill Test Certificate documenting 304 and 316L chemical composition (Cr, Ni, Mo content) and mechanical properties per GB standard
- CE certificate confirming compliance with EN 10219 for cold-formed welded stainless steel hollow sections
- ISO 9001:2015 quality management system certificate covering ERW welding and surface treatment processes
- SGS or BV third-party inspection report verifying dimensional tolerance (±1%), surface finish grade, and weld quality
- Material traceability by heat number linking each tube to its original melt chemistry and production batch
- Customs documents including packing list, bill of lading, and certificate of origin for destination-country clearance
Packaging, Loading & Delivery
- BA finish and mirror polish tubes wrapped in protective film with non-abrasive separators between layers to prevent surface scoring during transit
- Brushed and satin finish tubes bundled with edge protectors and steel strips, sized to match 6m standard length for efficient container loading
- Custom-cut lengths (1m–3m) loaded with interleaved cardboard dividers to maintain finish integrity and maximize container space utilization
- Heat number and steel grade (201/304/316L) marked on each tube end with stenciled labels for on-site identification and traceability
- Professional container loading plan optimized for square and rectangular tube nesting, reducing transit movement and corner damage
- FOB, CIF, and DDP shipping terms available with full export documentation and real-time tracking until destination port
Getting Your Quote and Material Certification
Submit your required steel grade (201, 304, 316L, or 316Ti), section dimensions, wall thickness, surface finish, and total quantity to receive a detailed quotation with unit pricing, production lead time, and shipping terms within 12 hours. We provide mill test certificates and can arrange SGS/BV third-party inspection before shipment. For non-standard sizes or custom lengths outside the 10mm × 20mm to 100mm × 200mm range, our engineering team reviews feasibility and confirms tooling requirements.
Request Your Stainless Steel Tube Quotation
Send your specifications, steel grade, surface finish, and destination port to receive pricing and mill test certificate samples.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
