Stainless Steel Coil Tube (Coiltube) — Product No. 1016
Product Overview
The Stainless Steel Coil Tube (Coiltube), designated as Product No. 1016 by Wenzhou Jixing Metal Materials Co., Ltd., is a high-performance cold-worked tubular product supplied in continuous coil form. This product represents a critical intermediate material in the fabrication of seamless stainless steel tubes, offering superior formability, dimensional consistency, and metallurgical homogeneity compared to traditional cut-to-length pipe sections. The coil configuration enables continuous downstream processing through automated drawing, piercing, and cold-forging lines, thereby maximizing material utilization and minimizing manufacturing waste.
Coil tubes are manufactured from cold-rolled stainless steel strip wound into a continuous helical coil, which is subsequently pierced or drawn through a die to form seamless tubular geometry. The resulting product combines the mechanical integrity of seamless tubes with the logistical and economic advantages of coil delivery.
Material & Properties
Stainless Steel Coil Tubes are predominantly fabricated from austenitic, ferritic, and duplex stainless steel grades, selected based on end-use requirements for corrosion resistance, mechanical strength, and weldability.
Commonly Available Grades
- Austenitic Grades: AISI 304 (UNS S30400), AISI 316L (UNS S31603), AISI 321 (UNS S32100), AISI 304L (UNS S30403)
- Ferritic Grades: AISI 430 (UNS S43000), AISI 409 (UNS S40900)
- Duplex Grades: 2205 (UNS S32205), 2507 (UNS S32750)
- Super-Austenitic Grades: 904L (UNS N08904), 6Mo (UNS N08060)
Typical Mechanical Properties (Annealed Condition)
- Tensile Strength (UTS): 515–720 MPa (75,000–104,000 psi)
- Yield Strength (0.2% offset): 205–310 MPa (30,000–45,000 psi)
- Elongation: ≥ 40% (minimum)
- Hardness: 110–200 HV (depending on grade and temper condition)
- Corrosion Resistance: Excellent resistance to atmospheric, chemical, and intergranular corrosion environments
Specifications
| Parameter | Specification Range | Unit |
|---|---|---|
| Outer Diameter (OD) | 4.0 – 60.0 | mm |
| Wall Thickness | 0.2 – 5.0 | mm |
| Coil Inner Diameter | 300 – 600 | mm |
| Coil Outer Diameter | 800 – 1,500 | mm |
| Coil Weight | 200 – 5,000 | kg |
| Surface Finish | 2B, BA (Bright Annealed), No.4 Brushed, Mirror (8K), Pickled & Passivated | — |
| Surface Roughness (Ra) | 0.05 – 0.8 | μm |
| Dimensional Tolerance (OD) | ± 0.1 – ± 0.5 | mm |
| Dimensional Tolerance (Wall) | ± 0.05 – ± 0.2 | mm |
| Straightness | ≤ 1.0 | mm/m |
| Applicable Standards | ASTM A213, ASTM A312, EN 10216-5, EN 10217-7, GB/T 12771, JIS G3459 | — |
| Temperature Range (Operating) | −196 °C to +870 °C | °C |
Manufacturing Process
The production of Stainless Steel Coil Tubes at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous, multi-stage manufacturing sequence designed to ensure metallurgical integrity and dimensional precision:
- Strip Selection & Incoming Inspection: Cold-rolled stainless steel strip is sourced from certified mills and subjected to spectrographic analysis, mechanical testing, and visual surface inspection to verify conformance with specified grades and tolerances.
- Edge Milling & Cleaning: Strip edges are milled to remove scale, burrs, and surface defects. The strip is subsequently cleaned using alkaline degreasing and acid pickling to eliminate contaminants prior to forming.
- Coil Winding & Annealing: The prepared strip is wound into a continuous coil. Inter-coil annealing may be performed to relieve residual stresses and stabilize the microstructure.
- Piercing / Forming: The coil is fed through a continuous piercing mill or cold-drawing die system to form the seamless tubular geometry. Process parameters (reduction ratio, temperature, lubrication) are tightly controlled to prevent material folding and ensure uniform wall thickness.
- Heat Treatment (Solution Annealing): Tubes are solution-annealed at temperatures between 1050 °C and 1150 °C followed by rapid quenching to achieve a fully austenitic microstructure, maximize corrosion resistance, and eliminate sensitization.
- Pickling & Passivation: Post-heat-treatment oxide scale is removed via controlled acid pickling. A subsequent passivation treatment establishes a stable chromium oxide passive film on the surface.
- Dimensional Verification & Non-Destructive Testing (NDT): Each coil undergoes ultrasonic testing (UT) for wall thickness uniformity, eddy current testing (ECT) for surface and near-surface defects, and hydrostatic pressure testing to verify structural integrity.
- Final Coiling & Packaging: Finished coils are wound onto appropriate cores, wrapped with protective moisture-barrier film, and secured with steel strapping for shipment.
Applications
Stainless Steel Coil Tubes find extensive application across multiple high-demand industrial sectors:
- Automotive Industry: Exhaust systems, fuel lines, turbocharger housings, and structural components requiring corrosion resistance and high-temperature stability.
- Food Processing & Pharmaceutical: Hygienic-grade piping, heat exchangers, and process vessels where cleanability and biocompatibility are paramount.
- Petrochemical & Oil/Gas: Subsea pipelines, heat exchanger tubes, and chemical processing equipment exposed to aggressive corrosive media.
- Medical Devices: Surgical instruments, implant fabrication stock, and diagnostic equipment housings requiring ultra-clean surface finishes.
- Architecture & Construction: Structural tubing, railings, and decorative elements for both interior and exterior applications.
- Energy Sector: Solar thermal absorber tubes, nuclear reactor coolant loops, and wind turbine structural components.
- Electronics & Precision Engineering: Heat sinks, vacuum chamber components, and precision-fitted mechanical assemblies.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring full traceability and regulatory compliance:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- ISO 45001:2018 — Occupational Health and Safety Management System certification
- EN 10204 Type 3.1 — Inspection Certificate (independent third-party verification)
- EN 10204 Type 3.2 — Material Test Report (mill-level documentation)
- Mill Test Certificates (MTC) — Provided for every batch with full chemical composition and mechanical property data
- RoHS & REACH Compliance — Certified free of restricted hazardous substances per EU directives
- PED (Pressure Equipment Directive 2014/68/EU) — Compliance for pressure-containing applications
Unique Selling Points
- Continuous Coil Configuration: Eliminates weld seams inherent to ERW (Electric Resistance Welded) alternatives, ensuring superior fatigue resistance and leak-tight integrity.
- Superior Formability: Cold-worked austenitic microstructure provides exceptional deep-drawability and bendability, reducing secondary forming operations.
- Wide Grade Availability: Single-source access to austenitic, ferritic, duplex, and super-austenitic grades simplifies supply chain management.
- Precision Dimensional Control: Tight tolerances on OD, wall thickness, and straightness minimize downstream machining requirements and scrap rates.
- Full Traceability: Each coil is serialized with batch-level documentation linking to mill heat numbers, ensuring complete material provenance.
- Custom Surface Finishes: Available in 2B, BA, brushed, and mirror finishes to meet exact application aesthetics and functional requirements.
Note: All specifications are subject to verification against the applicable standard edition in force at the time of order. Custom specifications and non-standard grades are available upon request with minimum order quantities and lead-time adjustments.