Non-Standard & Extreme Specification Stainless Steel Coil Tubes
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. specializes in the manufacture of precision stainless steel coil tubes engineered to meet demanding non-standard and extreme specification requirements that exceed conventional industry tolerances. Our facility is uniquely equipped to produce coil tubes with ultra-thin wall thicknesses below 0.5 mm, heavy-wall configurations exceeding 3.0 mm, and custom outer diameters (OD) outside standard series dimensions. These specialized products serve critical applications where standard catalog tubing cannot meet the geometric, mechanical, or thermal performance demands of the end-use system.
Material & Properties
Our non-standard coil tubes are fabricated from a comprehensive range of austenitic, duplex, and super-austenitic stainless steel grades, including but not limited to:
- 304 / 304L — General corrosion resistance with excellent formability for ultra-thin wall applications
- 316 / 316L — Enhanced chloride and pitting resistance for marine and chemical service
- 321 / 347 — Stabilized grades for high-temperature heat exchanger and furnace applications
- 904L — Superior resistance to reducing acids and aggressive chemical environments
- Duplex 2205 / Super Duplex 2507 — High strength-to-weight ratio for thick-wall pressure applications
All materials conform to ASTM, EN, JIS, and GB standards with full chemical composition and mechanical property traceability from mill certificates to finished product.
Specifications
| Parameter | Standard Range | Non-Standard / Extreme Capability |
|---|---|---|
| Outer Diameter (OD) | 3.0 – 150.0 mm | Custom OD per customer drawing (±0.05 mm tolerance) |
| Wall Thickness — Thin | ≥ 0.5 mm | Down to 0.10 mm (ultra-thin, foil-grade) |
| Wall Thickness — Thick | ≤ 3.0 mm | Up to 8.0 mm (heavy-wall, seamless) |
| Coil Length | 50 – 200 m | Up to 500 m continuous coil |
| Surface Finish | 2B, BA | Mirror (Ra ≤ 0.4 μm), Pickled & Passivated, Custom |
| Temperature Range | −196 °C to +870 °C | Cryogenic to high-temperature service verified |
| Pressure Rating | Per ASME B31.3 | Custom engineering per application |
Manufacturing Process
The production of non-standard and extreme-specification coil tubes demands advanced metallurgical engineering and precision forming technology. Our manufacturing workflow includes:
- Hot Rolling & Annealing — Billet or wire rod is hot-rolled to approximate dimensions, followed by full annealing to restore ductility and refine grain structure.
- Pilgering / Cross-Rolling — For thick-wall tubes, pilger mills reduce OD and wall thickness to near-final dimensions with tight concentricity control.
- Cold Drawing & Sizing — Multi-pass cold drawing achieves final dimensions with ultra-precise tolerances, particularly critical for wall thicknesses below 0.5 mm.
- Intermediate Annealing — Scheduled annealing cycles prevent work-hardening and maintain dimensional stability throughout the forming sequence.
- Coiling & Straightening — Tubes are coiled at controlled tension to prevent ovality and spring-back, ensuring consistent coil geometry.
- Surface Treatment — Final pickling, passivation, and optional polishing to achieve specified surface finish and corrosion resistance.
- Non-Destructive Testing (NDT) — 100% eddy current and hydrostatic testing to verify wall integrity, particularly at extreme thin-wall and thick-wall configurations.
Due to the specialized nature of these products, non-standard specifications require frequent die changes and result in lower material yield rates compared to standard production runs. A specification premium of 10%–30% is applied to reflect the increased tooling costs, reduced material utilization, and extended setup time inherent to extreme and custom geometry manufacturing.
Applications
- Cryogenic Systems — Ultra-thin wall tubing for LNG heat exchangers, cryogenic piping, and superconducting magnet cooling circuits
- Medical Devices — Precision tubing for endoscopes, surgical instruments, and implantable catheter components
- Automotive Exhaust & Turbochargers — Heavy-wall tubing for high-temperature exhaust manifolds and turbine housings
- Petroleum & Chemical Processing — Thick-wall tubing for high-pressure reactors, distillation columns, and acid service heat exchangers
- Aerospace — Custom OD tubing for fuel lines, hydraulic systems, and turbine engine components
- Food & Pharmaceutical — Mirror-finish tubing for hygienic processing equipment and CIP/SIP systems
- Electronics & Semiconductor — Ultra-thin capillary tubes for vacuum systems and gas flow control
Quality Certifications & Standards
Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems and holds the following certifications:
- ISO 9001:2015 — Quality Management System
- ISO 14001:2015 — Environmental Management System
- EN 10204 3.1 / 3.2 — Inspection documentation and third-party certification
- ASME Section IX — Welding procedure qualification
- NACE MR0175 / ISO 15156 — Sulfide stress cracking resistance (for oil & gas applications)
Every non-standard coil tube lot is accompanied by a full material traceability package including mill test certificates, dimensional inspection reports, NDT records, and surface finish verification. Third-party inspection by entities such as SGS, BV, or TUV is available upon request.
Value-Added Services
Recognizing the complexity of non-standard specifications, our engineering team provides:
- Pre-production feasibility analysis and DFM (Design for Manufacturability) review
- Custom tooling and die fabrication for unique OD and wall combinations
- Post-forming secondary operations: cutting, bending, welding, threading, and end-finishing
- Technical consultation on grade selection, wall thickness optimization, and cost-performance trade-offs
- Expedited sampling and prototype programs for rapid product development cycles
Note: Due to the specialized nature of non-standard and extreme-specification coil tube production, lead times may vary based on tooling availability, material grade, and order quantity. Customers are encouraged to engage our technical sales team early in the design phase to optimize specifications for manufacturability and cost efficiency while ensuring full compliance with performance requirements.