Stainless Steel Coil Tube (Coiltube) — Technical Product Specification
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
Product Category: Stainless Steel Coil Tube / Continuous Coil Pipe (盘管)
Product Code: 1065
Product Overview
The Stainless Steel Coil Tube is a continuously wound, seamless tubular product formed through precision cold-drawing or cold-rolling processes, supplied in a coiled configuration to facilitate downstream forming, bending, and fabrication without requiring welding at intermediate joints. This product represents an advanced application of high-precision coil tube manufacturing technology, drawing upon the latest developments in China's metallurgical equipment and production methodology.
Coil tubes offer significant advantages over straight-length tubing in terms of material utilization efficiency, production continuity, and dimensional consistency. The continuous winding format eliminates the need for butt welding during coil-to-coil transitions, ensuring superior mechanical integrity and corrosion resistance throughout the product length.
Material & Properties
Available Grades
- 304 / AISI 304 (UNS S30400): Austenitic stainless steel with excellent general corrosion resistance; suitable for food-grade and chemical processing applications.
- 316 / AISI 316 (UNS S31600): Molybdenum-enhanced austenitic grade offering superior resistance to pitting and crevice corrosion in chloride environments.
- 316L / AISI 316L (UNS S31603): Low-carbon variant of 316; ideal for welded assemblies requiring high corrosion resistance and resistance to intergranular corrosion.
- 321 / AISI 321 (UNS S32100): Titanium-stabilized austenitic grade providing enhanced resistance to sensitization at elevated temperatures.
- 304L / AISI 304L (UNS S30403): Low-carbon variant of 304; recommended for applications involving welding or high-temperature service.
Mechanical Properties (Typical — Annealed Condition)
| Property | 304 / 304L | 316 / 316L | 321 |
|---|---|---|---|
| Tensile Strength (Rm) | ≥ 520 MPa | ≥ 515 MPa | ≥ 515 MPa |
| Yield Strength (Rp0.2) | ≥ 205 MPa | ≥ 170 MPa | ≥ 205 MPa |
| Elongation (A50) | ≥ 40% | ≥ 35% | ≥ 35% |
| Density | 8.0 g/cm³ | 8.0 g/cm³ | 8.0 g/cm³ |
| Maximum Service Temperature | 870°C | 925°C | 900°C |
| Crystal Structure | Austenitic (FCC) | Austenitic (FCC) | Austenitic (FCC) |
Specifications
| Parameter | Specification Range |
|---|---|
| Outer Diameter (OD) | Φ3.0 mm – Φ50.8 mm (customizable up to Φ100 mm) |
| Wall Thickness | 0.25 mm – 5.0 mm |
| Coil Length | 50 m – 500 m (continuous, spliced-free) |
| Coil Inner Diameter (ID) | 100 mm / 150 mm / 200 mm (standard options) |
| OD Tolerance | ±0.05 mm (precision grade); ±0.10 mm (standard grade) |
| Wall Thickness Tolerance | ±0.02 mm (precision grade); ±0.05 mm (standard grade) |
| Roundness | ≤ 0.05 mm |
| Surface Finish | Bright Annealed (BA), 2B, No.4 Brushed, Mirror (#8), Matte |
| End Condition | Plain, Beveled, or Custom-cut |
| Delivery Condition | Annealed, Cold Worked, or Solution Treated |
Manufacturing Process
The production of high-precision stainless steel coil tubes follows a rigorous multi-stage process that ensures dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Selection: High-purity stainless steel strip or billet sourced from certified mills, subjected to incoming quality inspection including spectrographic analysis for chemical composition verification.
- Forming / Cold Drawing: Precision forming dies are employed to shape the strip into tubular configuration. For seamless coil tubes, cold drawing through calibrated dies achieves tight dimensional tolerances without thermal distortion.
- Welding (if applicable): For welded coil tubes, high-frequency induction welding (HFW) or laser welding is utilized, followed by inline OD sizing and wall thickness correction via roll stands.
- Continuous Annealing: The formed tube passes through a continuous annealing furnace (typically a hydrogen or nitrogen atmosphere bell furnace) to relieve internal stresses, restore ductility, and achieve the desired microstructure. Temperature profiles are precisely controlled to prevent grain growth and ensure uniform properties.
- Surface Treatment: Acid pickling and passivation remove scale and impurities, forming a stable chromium oxide passive layer. Additional surface finishing (polishing, brushing, or mirror processing) is applied as specified.
- Coiling: The finished tube is wound onto precision mandrels at controlled tension to maintain dimensional stability. Protective end caps and wrapping materials prevent handling damage.
- Quality Inspection: Non-destructive testing (NDT) including eddy current inspection, hydrostatic pressure testing, and dimensional gauging ensures compliance with specified tolerances and absence of internal/external defects.
Applications
- Automotive Industry: Fuel lines, exhaust system components, air conditioning tubing, hydraulic lines, and brake system tubing.
- Medical & Pharmaceutical: Instrument tubing, dialysis equipment, endoscopic device housings, and pharmaceutical fluid transport systems.
- Food & Beverage Processing: Sanitary piping, brewing equipment, dairy processing lines, and food-grade fluid transfer systems.
- Chemical Processing: Corrosive fluid transport, reactor cooling loops, and chemical dosing systems requiring high corrosion resistance.
- Oil & Gas: Subsea umbilicals, chemical injection lines, and offshore platform tubing.
- Electronics & Heat Exchange: Heat exchanger tubes, condenser coils, and electronic cooling circuits.
- Construction & Architecture: Structural tubing, handrail systems, and decorative architectural elements.
- Medical Device Manufacturing: Precision tubing for surgical instruments, catheter bodies, and implant components.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System certification ensuring consistent production quality and continuous improvement.
- ISO 14001 — Environmental Management System compliance for sustainable manufacturing practices.
- ISO 45001 — Occupational Health and Safety Management System certification.
- EN 10204 3.1 — Third-party material inspection certificates for traceability and compliance verification.
- API Standards — Available for oil and gas sector applications (API 5L, API 5CT compliance upon request).
- ASTM Standards — Product manufactured and tested in accordance with ASTM A213, A269, A554, and related specifications.
- GB/T Standards — Full compliance with Chinese National Standards (GB/T 14976, GB/T 13296, GB/T 21832) for domestic market certification.
- Food-Grade Compliance — NSF/ANSI 61 certification available for potable water applications.
- Material Traceability — Full mill certification with heat number traceability from raw material to finished product.
Unique Selling Points
- Superior Dimensional Precision: Tight tolerances (±0.05 mm OD, ±0.02 mm wall thickness) achieved through advanced cold-drawing and inline correction technology, enabling direct use in precision engineering applications without secondary machining.
- Continuous Splice-Free Length: Extended coil lengths up to 500 meters without welding splices, reducing assembly time and eliminating potential failure points in critical applications.
- High Material Utilization: Coiled delivery format minimizes cutting waste and reduces downstream processing requirements, delivering cost efficiency to end users.
- Advanced Surface Quality: Multi-stage surface treatment processes deliver consistent, defect-free finishes suitable for demanding hygiene and aesthetic requirements.
- Customization Capability: Flexible manufacturing parameters allow customization of dimensions, surface finish, delivery condition, and coil configuration to meet specific customer requirements.
- Full Traceability: End-to-end quality documentation with chemical analysis, mechanical test reports, and dimensional verification data for every production lot.
Note: All specifications are subject to engineering approval. Custom orders require submission of detailed technical drawings and performance requirements. Wenzhou Jixing Metal Materials Co., Ltd. reserves the right to modify specifications with prior notification to customers. For detailed material certifications and test reports, please contact the technical sales department.