BA Bright Annealed Surface Stainless Steel Coil Tube
Product Overview
The BA (Bright Annealed) Surface Stainless Steel Coil Tube is a precision-engineered coiled tubing product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product features a superior bright annealed outer surface finish, delivering exceptional aesthetic quality and functional performance suitable for both decorative and general industrial applications. The BA surface treatment preserves the original metallurgical luster of the annealed steel, providing a smooth, reflective, and corrosion-resistant exterior that distinguishes it from conventional pickled or polished finishes.
Available in standard stainless steel grades including 304, 304L, 316, 316L, 321, 310S, and custom alloy compositions, this coil tube product combines the flexibility of coiled form with the visual and surface integrity demands of high-end manufacturing sectors.
Material & Properties
- Base Material: Austenitic stainless steel grades (304, 304L, 316, 316L, 321, 310S, 904L, and custom alloys)
- Surface Finish: BA (Bright Annealed) — Original annealed luster preserved
- Surface Roughness: Ra ≤ 0.4 μm (outer surface)
- Metallurgical State: Fully annealed (soft/annealed condition), ensuring maximum ductility and formability
- Corrosion Resistance: Excellent resistance to atmospheric, chemical, and intergranular corrosion due to protective chromium oxide film formed during controlled-atmosphere annealing
- Surface Quality: Free from scale, discoloration, pitting, and surface defects; maintains a uniform mirror-like appearance
Specifications
| Parameter | Specification | Standard / Tolerance |
|---|---|---|
| Outer Diameter | 3 mm – 150 mm | ±0.1 mm |
| Wall Thickness | 0.3 mm – 6.0 mm | ±0.05 mm |
| Coil Inner Diameter | 50 mm – 300 mm | As per customer requirement |
| Surface Roughness (Outer) | Ra ≤ 0.4 μm | BA Bright Annealed |
| Surface Finish (Inner) | Pickled / BA / Custom | As specified |
| Material Grades | 304, 304L, 316, 316L, 321, 310S, 904L, Custom | ASTM / AISI / GB |
| Manufacturing Method | Seamless / Welded (per customer spec) | ASTM A213 / A269 / GB/T 12771 |
| Heat Treatment | Bright Annealed (Controlled Atmosphere) | Scale-free, no decarburization |
| Delivery Form | Coil / Coil on Spool | Protective packaging available |
| Applicable Standards | ASTM A213, ASTM A269, ASME SA-213, GB/T 12771, EN 10216 | — |
Manufacturing Process
The BA Bright Annealed Surface Stainless Steel Coil Tube undergoes a meticulously controlled multi-stage manufacturing process to achieve its exceptional surface quality and mechanical properties:
- Raw Material Selection: High-purity stainless steel wire rod or strip is sourced from certified mills, ensuring compliance with specified alloy compositions and mechanical properties.
- Precision Forming: The material is formed into tube geometry through cold-drawing or seamless piercing processes, achieving tight dimensional tolerances and uniform wall thickness.
- Coiling: The formed tube is wound onto precision spools to maintain coil geometry and prevent mechanical deformation or surface damage.
- Bright Annealing (Controlled Atmosphere): The coil tube is annealed in a protective atmosphere (typically dissociated ammonia or controlled hydrogen/nitrogen mixtures) at temperatures between 1050°C and 1150°C. This process eliminates cold-work stresses, restores full ductility, and — critically — prevents the formation of oxide scale on the tube surface, preserving the original bright luster.
- Surface Inspection: Each coil is inspected for surface roughness (Ra ≤ 0.4 μm), visual appearance, and dimensional accuracy using profilometers and automated optical systems.
- Final Quality Control: Chemical composition analysis (OES), mechanical testing (tensile, hardness), and hydrostatic testing are performed to certify product compliance.
Key Selling Points
- Superior Surface Integrity: The controlled-atmosphere bright annealing process eliminates oxide scale formation entirely, resulting in a pristine, reflective surface with Ra ≤ 0.4 μm — superior to conventional acid pickling or mechanical polishing.
- Elimination of Secondary Finishing: The BA surface meets decorative and general industrial appearance requirements directly, reducing or eliminating the need for additional polishing, passivation, or surface treatment steps, thereby lowering total cost of ownership.
- Consistent Metallurgical Quality: The fully annealed condition ensures maximum ductility and formability, enabling downstream bending, forming, and welding operations without cracking or work-hardening issues.
- Enhanced Corrosion Performance: The absence of surface scale and defects ensures an uninterrupted passive chromium oxide film, delivering optimal long-term corrosion resistance in aggressive environments.
- Flexible Coiled Delivery: The coil format maximizes material utilization, reduces cutting waste, and facilitates automated forming and fabrication lines.
- Customization Capability: Wenzhou Jixing Metal Materials Co., Ltd offers tailored solutions in grade, dimensions, and coil specifications to meet diverse project requirements.
Applications
The BA Bright Annealed Surface Stainless Steel Coil Tube is ideally suited for applications demanding both functional performance and high aesthetic standards:
- Architectural & Decorative Applications: Building facades, handrails, balustrades, elevator interiors, signage, and decorative trim where a polished, scale-free appearance is essential.
- Food & Beverage Processing: Hygienic piping systems, food processing equipment, dairy and beverage machinery where surface cleanliness and corrosion resistance are critical.
- Medical & Pharmaceutical Equipment: Surgical instrument housings, pharmaceutical processing lines, and medical device components requiring sterile, smooth surfaces.
- Automotive Industry: Exhaust system components, fuel lines, decorative exterior trim, and structural tubing requiring high surface quality and corrosion resistance.
- General Industrial Applications: Chemical processing equipment, heat exchanger tubes, fluid transfer systems, and structural components where appearance and corrosion resistance are combined requirements.
- Appliances & Consumer Products: High-end appliance housings, lighting fixtures, and consumer electronics enclosures.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- Product Standards: ASTM A213, ASTM A269, ASME SA-213, GB/T 12771, EN 10216-5
- Material Certification: Mill test certificates (MTC) with EN 10204 3.1 certification available
- Testing Protocols: Chemical analysis (OES), tensile testing, hardness testing, hydrostatic pressure testing, surface roughness profiling, and visual inspection per ASTM E1025
- Traceability: Full lot and heat number traceability from raw material through final delivery
Note: All specifications are subject to customer requirements and applicable standards. Wenzhou Jixing Metal Materials Co., Ltd is committed to delivering premium-quality BA surface stainless steel coil tubes that meet the most demanding aesthetic and performance criteria in decorative and industrial applications. For custom specifications, dimensional requirements, or grade selections, please contact our technical team for a detailed quotation and engineering consultation.