Stainless Steel Coil Tube (盘管 / Coiltube) — Chassis Piping Application Series
Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
Product Reference No.: 1249
1. Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered continuous length tubing product designed specifically for automotive chassis piping systems. Manufactured by Wenzhou Jixing Metal Materials Co., Ltd., this product is supplied in coiled form to facilitate downstream processing, including cutting, bending, and forming operations required in chassis assembly lines. The coil tube is produced through advanced riveting and cold-drawing technologies, ensuring dimensional consistency, mechanical integrity, and superior corrosion resistance throughout its service life.
This product category is distinguished by its application-specific design philosophy, where the tubing geometry, wall thickness, and material composition are optimized to withstand the dynamic loading conditions, thermal cycling, and corrosive environments encountered in automotive chassis piping systems — including brake lines, fuel delivery lines, and hydraulic actuation circuits.
2. Material & Properties
The coil tube is fabricated from high-grade austenitic stainless steel, with the following typical material specifications:
- Base Alloy: AISI 304 (UNS S30400) or AISI 316L (UNS S31603) austenitic stainless steel
- Carbon (C): ≤ 0.08% (304) / ≤ 0.03% (316L)
- Chromium (Cr): 18.0% – 20.0%
- Nickel (Ni): 8.0% – 10.5%
- Molybdenum (Mo): 2.0% – 3.0% (316L only)
- Tensile Strength (UTS): ≥ 520 MPa (cold-worked condition)
- Yield Strength: ≥ 205 MPa
- Elongation: ≥ 40%
- Corrosion Resistance: Excellent resistance to atmospheric corrosion, mild acids, and alkaline solutions
- Operating Temperature Range: −196°C to +870°C (304); −196°C to +425°C (316L)
3. Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Outer Diameter (OD) | 6.0 mm – 25.4 mm (customizable) | ASTM A269 / GB/T 12771 |
| Wall Thickness | 0.5 mm – 2.0 mm | ASTM A269 / GB/T 12771 |
| OD Tolerance | ±0.1 mm | ISO 6507 |
| Wall Thickness Tolerance | ±10% of nominal | ASTM A269 |
| Coil Diameter | 500 mm – 1200 mm | Manufacturer standard |
| Coil Length per Spool | 50 m – 300 m | Manufacturer standard |
| Surface Finish | Mirror polished / Commercial (2B) / Matte | ASTM A270 |
| End Condition | Plain cut / Beveled / Cup-sealed | Customer specification |
| Heat Treatment | Solution annealed (1050°C – 1150°C, water quench) | ASTM A269 |
| Welding Seam | Seamless or laser-welded (as applicable) | ASTM A213 |
4. Manufacturing Process
The production of this coil tube follows a rigorous multi-stage manufacturing workflow, incorporating specialized riveting machine technology for chassis piping applications:
- Raw Material Preparation: High-purity stainless steel wire rod or strip is inspected for chemical composition and mechanical properties prior to processing.
- Pipe Forming (Cross-Rolling / Extrusion): The raw material is formed into a tubular blank through cross-rolling or extrusion methods, establishing the initial diameter and wall geometry.
- Pilot Tube Riveting Machine Operation: A dedicated riveting machine (铆管机) is employed to achieve precise dimensional control of the pilot tube. This specialized equipment ensures consistent internal diameter, wall uniformity, and surface integrity — critical parameters for chassis piping applications where fluid flow dynamics and pressure containment are paramount.
- Cold Drawing & Sizing: The tube is cold-drawn through precision-die sets to achieve final dimensions within tight tolerances. This process enhances mechanical properties through work hardening while maintaining dimensional accuracy.
- Heat Treatment (Solution Annealing): The drawn tube undergoes solution annealing at 1050°C – 1150°C followed by rapid water quenching to restore full austenitic microstructure, eliminate residual stresses, and maximize corrosion resistance.
- Pickling & Passivation: The tube surface is chemically treated to remove scale, oxide films, and contaminants, restoring the natural chromium oxide passive layer.
- Surface Finishing: Depending on application requirements, the tube may undergo mirror polishing, mechanical buffing, or chemical passivation to achieve the specified surface roughness (Ra ≤ 0.4 μm for mirror finish).
- Coiling & Packaging: The finished tube is coiled on precision pay-off reels, protected with VCI (Vapor Corrosion Inhibitor) film or desiccant packaging, and secured with steel strapping for shipment.
5. Applications
The stainless steel coil tube from Wenzhou Jixing Metal Materials Co., Ltd. is primarily designed for the following industrial applications:
- Automotive Chassis Piping Systems: Brake fluid lines, fuel injection lines, hydraulic control circuits, and air conditioning refrigerant lines in commercial vehicles, heavy trucks, and passenger vehicles.
- Hydraulic & Pneumatic Systems: High-pressure fluid conveyance in industrial machinery, construction equipment, and agricultural implements.
- Medical Equipment: Tubing for medical gas delivery systems, surgical instrument housings, and diagnostic equipment enclosures.
- Food & Beverage Industry: Sanitary process lines, CIP (Clean-in-Place) compatible fluid transfer systems, and brewing equipment.
- Chemical Processing: Corrosive fluid transport in pharmaceutical manufacturing, semiconductor fabrication, and chemical plants.
- Oil & Gas Industry: Downhole tubing, wellhead assemblies, and subsea production systems.
- Architecture & Decorative Applications: Structural handrails, elevator guide rails, and precision architectural components.
6. Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality management systems and product certifications:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- ISO/TS 22163 — Automotive-specific quality management standard
- Product Standards: ASTM A269, ASTM A270, ASTM A213, GB/T 12771, GB/T 14976
- Material Testing: Chemical composition analysis (OES/ICP), mechanical testing (tensile, hardness, impact), hydrostatic pressure testing, dimensional inspection (CMM/laser), and surface defect detection (eddy current/ultrasonic)
- Traceability: Full heat-number traceability from raw material mill certificate through final product dispatch
- Third-Party Inspection: Available upon request (SGS, BV, TUV)
7. Unique Selling Points
Specialized Riveting Technology for Chassis Applications: The integration of a dedicated pilot tube riveting machine (铆管机) in the manufacturing process provides superior dimensional control and internal surface quality, directly addressing the critical requirements of automotive chassis piping systems where precision, reliability, and fatigue resistance are non-negotiable.
- Coiled Delivery Format: Enables continuous feed processing, reducing material waste, minimizing handling, and improving production line efficiency for downstream integrators.
- Customizable Specifications: Flexible OD, wall thickness, coil dimensions, and surface finish options to meet diverse OEM requirements.
- End-to-End Quality Control: From incoming material inspection through final coil verification, ensuring zero-defect delivery.
- Proven Chassis Piping Expertise: Deep technical knowledge of automotive chassis piping design requirements, supported by documented application engineering experience.
- Cost-Effective Solution: Optimized manufacturing processes deliver competitive pricing without compromising material integrity or dimensional accuracy.
Conclusion: The Stainless Steel Coil Tube (Product No. 1249) from Wenzhou Jixing Metal Materials Co., Ltd. represents a purpose-engineered solution for chassis piping and high-performance tubing applications. Combining premium austenitic stainless steel materials, specialized riveting machine technology, and rigorous quality assurance protocols, this product delivers the dimensional precision, mechanical reliability, and corrosion durability demanded by modern automotive and industrial applications.