Vertical Bright Annealed (BA) Stainless Steel Coil Tube
Product Overview
The Vertical Bright Annealed (BA) Stainless Steel Coil Tube is a premium-grade tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This coil tube is processed through a state-of-the-art vertical bright annealing furnace, distinguishing it from conventional horizontal furnace treatments. The vertical orientation ensures superior uniformity in heat distribution, elimination of roller marks, and delivery of an exceptional surface finish — making it the preferred parent tube material for high-end EP (Electro-Polished) tubing and mirror-finish applications.
Designed for demanding industrial and precision manufacturing sectors, this product represents the pinnacle of stainless steel coil tube processing, combining advanced metallurgical expertise with meticulous quality control at every stage of production.
Material & Properties
Available in a range of austenitic and specialty stainless steel grades, the coil tube delivers outstanding corrosion resistance, mechanical integrity, and surface aesthetics. The bright annealing process in a vertical furnace environment preserves the metal's natural passivation layer, resulting in a clean, oxide-free surface without the need for subsequent pickling or acid cleaning.
- Primary Grades: 304, 304L, 316, 316L, 321, 310S, and custom alloy compositions upon request
- Surface Finish: Bright annealed (BA) — achieving Ra ≤ 0.4 μm surface roughness
- Corrosion Resistance: Excellent resistance to intergranular corrosion, pitting, and stress corrosion cracking
- Mechanical Properties: Maintains optimal tensile strength and elongation post-annealing
- Chemical Purity: Ultra-low carbon options available for welding-critical applications
Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter | 3.0 mm – 150.0 mm (custom sizes available) |
| Wall Thickness | 0.3 mm – 8.0 mm (custom tolerances available) |
| Coil Inner Diameter | 150 mm – 300 mm |
| Coil Length | Up to 1,500 m per coil | Dimensional Tolerance | ±0.05 mm (OD), ±0.05 mm (WT) |
| Surface Roughness | Ra ≤ 0.4 μm (BA finish) |
| Heat Treatment | Vertical Bright Annealing (BA) |
| Applicable Standards | ASTM A269, ASTM A270, EN 10216-5, GB/T 14976 |
| Delivery Condition | Bright Annealed, Pickled & Passivated (optional) |
| Packaging | Wooden crate / steel drum with moisture-proof wrapping |
Manufacturing Process
The production of Vertical BA Stainless Steel Coil Tube follows a rigorously controlled multi-stage manufacturing workflow:
- Raw Material Selection: High-purity stainless steel strip from certified mills is inspected for chemical composition, mechanical properties, and surface integrity.
- Coiling & Forming: Precision coiling technology ensures uniform tube geometry with tight dimensional tolerances throughout the entire coil length.
- Welding (if applicable):strong> High-frequency induction welding (HFW) or TIG welding is performed under inert gas shielding to achieve defect-free weld seams.
- Vertical Bright Annealing: The coil tube is processed in a purpose-built vertical bright annealing furnace. Unlike horizontal furnaces, the vertical configuration allows gravity to distribute the tube uniformly, eliminating roller contact marks and ensuring even thermal exposure across the entire surface area. The furnace atmosphere is maintained under controlled reducing conditions (typically nitrogen or dissociated ammonia) to prevent oxidation.
- Cooling & Passivation: Controlled cooling rates preserve the bright surface finish, followed by optional passivation treatment to enhance long-term corrosion resistance.
- Quality Inspection: Every coil undergoes hydrostatic testing, dimensional verification, surface inspection, and chemical analysis prior to shipment.
Unique Selling Points
- Gravity-Uniform Annealing: The vertical furnace design ensures consistent heat distribution without the uneven pressure points common in horizontal furnace systems, delivering uniform microstructure and mechanical properties across the entire coil.
- Zero Roller Marks: The absence of roller supports during the annealing cycle guarantees a flawless, mark-free surface — critical for downstream applications requiring pristine aesthetics.
- Superior Surface Quality: Achieves a true bright annealed finish with minimal post-processing, reducing total manufacturing costs for end users.
- EP Tube & Mirror Tube Ready: Specifically engineered as the ideal parent material for electro-polished (EP) tubing and mirror-finish tube production, where surface perfection is non-negotiable.
- Consistent Quality: Advanced process control and real-time monitoring ensure batch-to-batch consistency in dimensions, surface finish, and metallurgical properties.
Applications
- High-End EP (Electro-Polished) Tubing: Parent tube for medical devices, pharmaceutical processing lines, and semiconductor equipment where ultra-smooth internal surfaces are mandated.
- Mirror-Finish Tubes: Raw material for optical instruments, decorative applications, and high-precision instrumentation.
- Food & Beverage Industry: Sanitary-grade tubing for dairy, brewing, and food processing systems requiring easy-clean surfaces.
- Medical & Pharmaceutical Equipment: Components for surgical instruments, infusion devices, and bioreactors.
- Semiconductor & Electronics: Ultra-pure gas delivery lines, vacuum chambers, and cleanroom piping.
- Chemical Processing: Corrosion-resistant tubing for aggressive chemical environments.
- Precision Engineering: Hydraulic systems, pneumatic cylinders, and high-pressure fluid conveyance.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and holds the following certifications and compliance standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001 — Environmental Management System
- ISO 45001 — Occupational Health & Safety Management
- CE Marking — European Conformity for pressure equipment
- EN 10204 3.1 — Material Test Certificate (Third-Party Verified)
- ASME / PED Compliance — Available for pressure vessel and piping applications
- Mill Test Reports (MTR) — Full chemical and mechanical analysis provided with every shipment
Why Choose Wenzhou Jixing? With decades of expertise in stainless steel tube manufacturing and a dedicated vertical BA furnace facility, Wenzhou Jixing Metal Materials Co., Ltd. delivers coil tubes that set the benchmark for surface quality and dimensional precision. Whether you require EP-grade parent tubes or mirror-finish coil stock, our vertical bright annealing technology provides the foundation for your highest-performance applications.