Stainless Steel Coil Tube (Coiltube) — Product No. 1572
1. Product Overview
The Stainless Steel Coil Tube (Coiltube), designated as Product No. 1572, is a precision-engineered continuous coil tubing manufactured by Wenzhou Jixing Metal Materials Co., Ltd. This product is produced in a coiled configuration, enabling seamless processing, downstream forming, and fabrication without the need for weld joints that would compromise structural integrity. Coil tubes are distinguished from straight-length tubes by their continuous, helical winding form, which facilitates efficient material utilization, reduced waste, and streamlined handling in high-volume manufacturing environments.
Wenzhou Jixing Metal Materials Co., Ltd leverages advanced cold-drawn and seamless tube manufacturing technologies to produce coil tubes that meet or exceed international standards for dimensional accuracy, mechanical properties, and surface finish. The product is designed for applications demanding superior corrosion resistance, hygienic performance, and long-term structural reliability in demanding industrial environments.
2. Material Composition & Mechanical Properties
2.1 Grade Designation
The coil tube is available in multiple austenitic stainless steel grades, with the primary offering being Grade 304 (UNS S30400) and Grade 316L (UNS S31603). Additional grades including 321, 310S, and 904L are available upon special order to address specific environmental or performance requirements.
2.2 Chemical Composition (Typical, wt%)
| Grade | C | Mn | P | S | Si | Cr | Ni | Mo | N |
|---|---|---|---|---|---|---|---|---|---|
| 304 | ≤0.08 | ≤2.00 | ≤0.045 | ≤0.030 | ≤0.75 | 18.0–20.0 | 8.0–10.5 | — | — |
| 316L | ≤0.03 | ≤2.00 | ≤0.045 | ≤0.030 | ≤0.75 | 16.0–18.0 | 10.0–14.0 | 2.0–3.0 | — |
2.3 Mechanical Properties (Annealed Condition)
| Property | Grade 304 | Grade 316L |
|---|---|---|
| Tensile Strength (MPa) | ≥515 | ≥485 |
| Yield Strength (MPa) | ≥205 | ≥170 |
| Elongation (%) | ≥40 | ≥40 |
| Hardness (HRB) | ≤95 | ≤95 |
| Density (g/cm³) | 7.93 | 7.98 |
2.4 Key Material Characteristics
- Corrosion Resistance: The high chromium content (≥18%) forms a passive chromium oxide layer that provides exceptional resistance to atmospheric, chemical, and aqueous corrosion. Grade 316L further incorporates molybdenum (2–3%) for enhanced pitting and crevice corrosion resistance in chloride-rich environments.
- Hygienic Performance: The austenitic microstructure supports electropolishing and passivation treatments, achieving surface roughness values as low as Ra 0.2 μm, essential for pharmaceutical and food-grade applications.
- Weldability: The low carbon content (especially in 316L, ≤0.03%) minimizes intergranular corrosion risk during welding, ensuring reliable fabrication and joint integrity.
- Temperature Tolerance: Suitable for continuous service temperatures ranging from cryogenic conditions (−196 °C) to 870 °C (Grade 304) and 925 °C (Grade 316L).
3. Dimensions & Specifications
3.1 Geometric Specifications
| Parameter | Specification |
|---|---|
| Outer Diameter (OD) | Φ3.0 mm – Φ168.3 mm (custom sizes available) |
| Wall Thickness | 0.25 mm – 12.0 mm |
| Coil Inner Diameter | Φ300 mm / Φ500 mm / Φ600 mm (configurable) |
| Coil Outer Diameter | ≤Φ1200 mm |
| Coil Weight | Up to 1,500 kg per coil (standard); up to 2,500 kg (special order) |
| Length per Coil | Continuous; typically 200 m – 2,000 m depending on OD and wall thickness |
3.2 Dimensional Tolerances
| Parameter | Tolerance (per ASTM A213 / A269) |
|---|---|
| Outer Diameter (OD ≤ 50 mm) | ±0.05 mm (precision grade); ±0.10 mm (standard) |
| Outer Diameter (OD > 50 mm) | ±0.15 mm (standard); ±0.08 mm (precision grade) |
| Wall Thickness (t ≤ 1 mm) | ±0.02 mm (precision grade); ±0.05 mm (standard) |
| Wall Thickness (t > 1 mm) | ±0.05 mm (standard); ±0.03 mm (precision grade) |
| Roundness | ≤0.5% of nominal OD |
| Coil Winding Tolerance | ±5 mm (radial deviation) |
3.3 Surface Finish Options
- Pickled & Passivated (P&P): Standard finish; smooth, uniform, corrosion-resistant surface suitable for general industrial applications.
- Baught & Pickled (B&P): Cold-worked finish providing enhanced mechanical strength with improved surface appearance.
- 2B Finish: Cold-rolled and annealed; moderate surface luster suitable for decorative and general-purpose applications.
- Mirror Polish (8K): Mechanical polishing to achieve Ra ≤ 0.1 μm; for architectural and high-visibility applications.
- Electropolished: Electrochemical polishing to Ra ≤ 0.2 μm; required for pharmaceutical, biotech, and food processing applications.
- Brushed / Hairline Finish: Directional surface texture for aesthetic and anti-glare applications.
4. Manufacturing Process
The production of stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorous multi-stage manufacturing process adhering to international quality management protocols:
- Raw Material Procurement: High-purity stainless steel billets or strip are sourced from certified mills. Incoming material undergoes spectrographic analysis (OES) to verify chemical composition compliance with ASTM, EN, or JIS standards.
- Piercing / Slitting: For seamless tube production, solid billets are heated to 1,150–1,250 °C and pierced on a Mannesmann-type piercing mill to produce a hollow shell. Alternatively, strip material is slit to the required width for ERW or laser-welded tube production.
- Hot Rolling & Sizing: The pierced shell is hot-rolled and reduced through a series of stands to achieve the approximate target dimensions, followed by hot sizing to refine the outer diameter.
- Pickling & Descaling: The hot-rolled tube is pickled in a mixed acid bath (HNO₃ + H₂SO₄) to remove scale and oxide layers, restoring the base metal's corrosion-resistant surface.
- Cold Drawing / Cold Rolling: The tube is cold-drawn through a series of dies to achieve precise dimensional tolerances, enhanced mechanical properties (strain hardening), and superior surface finish. This step is critical for achieving tight tolerance requirements.
- Solution Annealing: The cold-worked tube is solution-annealed at 1,040–1,120 °C (water or air quenched) to relieve residual stresses, restore full austenitic ductility, and re-establish the passive chromium oxide layer.
- Coiling: The finished tube is wound into coils using a precision coiling head that controls winding tension to prevent deformation, kinking, or ovality. The coil is then stabilized with strapping and protective wrapping.
- Quality Inspection: Each coil undergoes comprehensive inspection including dimensional measurement, visual examination, hydrostatic testing (where applicable), and surface defect detection (eddy current or ultrasonic testing).
5. Applications
The versatility of the stainless steel coil tube makes it suitable for a broad spectrum of industrial and commercial applications:
- Food & Beverage Processing: Hygienic-grade tubing for dairy processing, beverage conveying, and food-grade piping systems where contamination resistance is paramount.
- Pharmaceutical & Biotechnology: Electropolished tubing for CIP (Clean-in-Place) and SIP (Sterilize-in-Place) compatible process systems.
- Automotive Industry: Fuel lines, exhaust system components, and high-temperature hydraulic lines requiring corrosion and thermal resistance.
- Oil & Gas: Downhole tubing, chemical processing lines, and offshore platform piping systems exposed to aggressive chloride environments.
- Chemical Processing: Reactor internals, heat exchanger tubes, and process piping handling corrosive chemicals and acids.
- Medical Devices: Tubing for medical gas delivery systems, surgical instrument components, and implantable device housings.
- Construction & Architecture: Structural tubing, handrails, decorative elements, and facade systems requiring weathering resistance and aesthetic finish.
- Energy & Power Generation: Boiler tubes, heat exchanger elements, and solar thermal collector tubes.
- General Manufacturing: Raw material for tube processing, bending, welding, and fabrication operations where continuous coil supply improves production efficiency.
6. Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality assurance framework to ensure product conformity with global standards:
- ISO 9001:2015 — Quality Management Systems certification ensuring consistent product quality and process control.
- ISO 14001:2015 — Environmental Management Systems certification demonstrating commitment to sustainable manufacturing practices.
- ISO 45001:2018 — Occupational Health and Safety Management Systems certification.
- EN 10204 / EN 10204 3.1 — Material test certificates issued in accordance with European standards, providing full traceability of material origin, chemical analysis, and mechanical test results.
- ASTM Standards Compliance: Products conform to ASTM A213 (Seamless and Welded Austenitic Stainless Steel Tubing), ASTM A269 (Seamless and Welded Austenitic Stainless Steel Tubing for Chemical and Heat-Transfer Service), and ASTM A554 (Welded Austenitic Stainless Steel Tube for General Applications).
- EN Standards Compliance: Products conform to EN 10216-5 (Thick-walled tubes for technical uses) and EN 10217-7 (Welded austenitic stainless steel tubes).
- CE Marking: Available for products intended for the European Economic Area market.
- Mill Test Reports (MTR): Comprehensive documentation including chemical composition, mechanical properties, dimensional measurements, and heat treatment records provided with each shipment.
7. Unique Selling Points
- Continuous Coil Configuration: Eliminates butt welds and joint defects, providing uniform material properties along the entire tube length and enabling seamless downstream processing.
- Wide Dimensional Range: Capabilities spanning from micro-tubing (Φ3.0 mm) to large-diameter pipe (Φ168.3 mm) with wall thicknesses from 0.25 mm to 12.0 mm, covering virtually all industrial requirements.
- Precision Tolerances: Advanced cold-drawing technology achieves dimensional accuracy to ±0.02 mm, suitable for high-precision applications in medical, aerospace, and instrumentation sectors.
- Multi-Grade Availability: Full range of austenitic, duplex, and super-austenitic grades available from a single supplier, simplifying procurement and ensuring material consistency.
- Custom Surface Finishes: In-house capability for pickling, passivation, electropolishing, and mirror finishing eliminates the need for third-party post-processing.
- Full Traceability: Each coil is individually identified with heat number, grade, dimensions, and manufacturing date, enabling complete supply chain traceability.
- Cost Efficiency: Coil format reduces material waste by up to 15% compared to cut-length delivery, while minimizing handling and storage costs.
8. Packaging & Delivery
- Coils are wrapped with VCI (Vapor Corrosion Inhibitor) film and protected with corrugated cardboard or wooden packaging.
- Standard export packaging with wooden pallets and steel strapping for ocean freight.
- Custom packaging available upon request for sensitive or high-value shipments.
- Lead time: 15–30 days for standard orders; 45–60 days for special specifications or custom finishes.
Note: All specifications listed herein are subject to revision based on manufacturing updates and customer-specific requirements. Wenzhou Jixing Metal Materials Co., Ltd reserves the right to adjust tolerances and dimensions within the bounds of applicable international standards. For detailed technical data sheets and material certifications, please contact the sales engineering department directly.