Stainless Steel Coil Tube (Coiltube) — Product Technical Specification
1. Product Overview
The Stainless Steel Coil Tube (also referred to as Coiltube or Coiled Tubing) is a continuous-length tubular product manufactured from high-grade austenitic stainless steel wire, formed into a compact coil configuration for efficient storage, transportation, and downstream processing. This product line, produced by Wenzhou Jixing Metal Materials Co., Ltd., is engineered to meet demanding industrial applications requiring corrosion resistance, thermal stability, and mechanical integrity.
The coil tube format enables automated feeding into cutting, bending, and forming machinery — including specialized Heating Coil Tube Head Cutting Machines — which allow precise, high-volume production of finished components with minimal material waste. The continuous coil geometry significantly reduces manual handling and increases production throughput compared to discrete bar or pipe segments.
2. Material & Properties
2.1 Base Material Grades
- SUS304 / ASTM 304 — General-purpose austenitic stainless steel (18% Cr, 8% Ni); excellent corrosion resistance in atmospheric and mild chemical environments.
- SUS316 / ASTM 316 — Enhanced austenitic grade with 2–3% Molybdenum; superior resistance to pitting and crevice corrosion in marine and chemical processing applications.
- SUS321 / ASTM 321 — Titanium-stabilized austenitic grade; excellent resistance to intergranular corrosion at elevated temperatures (up to 870°C).
- SUS304L / ASTM 304L — Low-carbon variant of 304; optimized for welding applications requiring minimal sensitization.
2.2 Key Mechanical & Physical Properties
- Tensile Strength (UTS): ≥ 520 MPa (annealed condition)
- Yield Strength (0.2% proof stress): ≥ 205 MPa
- Elongation at Break: ≥ 35% (minimum, per ASTM A270)
- Hardness: 70–100 HRB (annealed); up to 320 HV (work-hardened)
- Density: 7.93 g/cm³
- Thermal Conductivity (at 20°C): 16.3 W/(m·K)
- Coefficient of Thermal Expansion (20–100°C): 17.3 × 10⁻⁶ /K
- Maximum Service Temperature: 870°C (SUS321); 800°C (SUS304/316)
2.3 Surface Finishes Available
- BA (Bright Annealed) — Mirror-smooth surface, no scale, ideal for decorative and sanitary applications.
- No. 4 Brushed — Uniform directional grain; widely used in architectural and appliance sectors.
- No. 8 Mirror — High-reflectivity polished finish (Ra ≤ 0.05 μm).
- Pickled & Passivated (2B) — Matte industrial finish with enhanced passive film integrity.
3. Specifications
| Parameter | Specification / Range |
|---|---|
| Outer Diameter (OD) | 1.0 mm – 12.0 mm (custom sizes available) |
| Wall Thickness (WT) | 0.2 mm – 1.5 mm |
| Inner Diameter (ID) | 0.6 mm – 10.0 mm |
| Coil Length (Continuous) | 50 m – 500 m per coil (typical) |
| Coil Inner Diameter | 150 mm – 400 mm |
| Coil Weight (Net) | 20 kg – 150 kg per coil |
| OD Tolerance | ±0.05 mm (precision grade); ±0.10 mm (standard) |
| WT Tolerance | ±10% (per ASTM A213 / A269) |
| Straightness | ≤ 1.5 mm/m (after uncoiling) |
| Material Standards | ASTM A213, ASTM A269, ASTM A270, EN 10216-5, JIS G3459 |
| Heat Treatment | Solution Annealed (1050–1150°C) + Water Quench |
| Non-Destructive Testing | 100% Eddy Current Testing (ECT); Hydrostatic Testing optional |
4. Manufacturing Process
The production of stainless steel coil tube follows a multi-stage manufacturing workflow, each step rigorously controlled to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Wire Drawing — Austenitic stainless steel rod is cold-drawn through multi-stage dies to achieve precise wire diameter with controlled work-hardening. Drawing lubricants (typically phosphate-based or PVA emulsions) ensure dimensional consistency and surface protection.
- Intermediate Annealing — Periodic solution annealing at 1050–1150°C relieves accumulated cold-work stresses, restoring ductility and preventing fracture during subsequent forming operations.
- Coiling (Tube Forming) — The drawn wire is fed into a seamless tube-forming machine (plug or roll-forming method), where it is shaped into a continuous tubular geometry while maintaining a coil configuration. The coil tube head cutting machine ensures clean, burr-free end preparation.
- Final Annealing & Pickling — The formed coil tube undergoes final solution annealing in a continuous belt furnace under protective atmosphere (H₂/N₂ or vacuum) to eliminate forming stresses. Subsequent pickling removes surface oxide scale; passivation restores the chromium oxide passive film.
- Surface Finishing — Depending on specification, the coil tube may undergo mechanical polishing, electropolishing, or chemical passivation to achieve the required surface roughness and corrosion resistance.
- Quality Inspection & Testing — Every coil undergoes 100% automated eddy current testing to detect internal and external defects (seams, cracks, thickness variations). Hydrostatic pressure testing (where applicable) verifies weld integrity and burst strength.
- Packaging & Marking — Coils are wrapped in moisture-proof PE film, secured with steel strapping, and palletized for export. Each coil is marked with heat number, grade, dimensions, and traceability identifiers.
5. Applications
Stainless steel coil tube finds extensive use across multiple industries due to its combination of corrosion resistance, formability, and hygienic surface properties:
- Medical & Pharmaceutical — Surgical instrument components, implant fabrication, dialysis tubing, and medical device housings (biocompatible, autoclavable).
- Food & Beverage Processing — Heat exchangers, pasteurization coils, sanitary piping, and food-grade tubing (FDA-compliant, easy to clean).
- Automotive & Aerospace — Exhaust system components, fuel lines, hydraulic tubing, and heat-resistant exhaust manifolds.
- Chemical & Petrochemical — Reaction vessel coils, distillation column internals, and process piping exposed to aggressive media.
- Electronics & Electrical — Heat sinks, sensor housings, wire harness components, and electromagnetic shielding tubes.
- Architectural & Decorative — Handrails, balustrades, furniture frames, lighting fixtures, and interior design elements.
- Energy Sector — Solar thermal collector tubes, geothermal heat exchangers, and cryogenic applications.
6. Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system ensuring consistent product conformity:
- ISO 9001:2015 — Quality Management System certification covering all manufacturing and inspection processes.
- ISO 14001:2015 — Environmental Management System demonstrating sustainable manufacturing practices.
- ISO 45001:2018 — Occupational Health & Safety Management System.
- EN 10204 3.1 — Third-party inspected material certificates provided with every shipment.
- CE Marking — Conformity with European directives for pressure equipment (PED 2014/68/EU) where applicable.
- NACE / AMPP — Compliance with corrosion engineering standards for oil & gas applications.
- Mill Test Reports (MTR) — Full chemical analysis and mechanical property data supplied per ASTM E1/E8/E290.
7. Unique Selling Points
- Continuous Coil Configuration — Enables high-speed automated cutting and forming, reducing material waste by up to 30% compared to discrete tube segments.
- Precision Dimensional Control — Tight tolerances (±0.05 mm OD) achieved through advanced cold-drawing and forming technology, suitable for high-precision assembly applications.
- 100% Non-Destructive Testing — Automated eddy current inspection ensures defect-free product delivery with full traceability.
- Customizability — Wide range of diameters, wall thicknesses, grades, and surface finishes available; custom coil sizes and packaging configurations to meet specific customer requirements.
- Full Traceability — Each coil is linked to its production heat number, enabling complete supply chain traceability from raw material to finished product.
- Technical Support — Dedicated engineering team provides application-specific material selection guidance, design consultation, and sample development services.
Note: All specifications are subject to engineering approval. Custom orders requiring non-standard dimensions, grades, or surface treatments should be discussed with the manufacturer's technical department for feasibility assessment and quotation.