Stainless Steel Coil Tube — High Straightness & Springback Control for Automated Bending
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. offers premium-grade stainless steel coil tube engineered for superior natural straightening performance and dimensional consistency. This product category is specifically designed for applications requiring precise automated processing, where post-unwinding straightness and controlled springback characteristics are critical to downstream manufacturing accuracy.
The coil tube is supplied in tightly wound coil form, enabling efficient material utilization and seamless integration into continuous processing lines. Upon unwinding, the tube exhibits predictable and uniform natural straightening behavior, characterized by a quantified deviation per unit length (mm/m), ensuring reliable feeding into automated bending machines and other precision fabrication equipment.
Material & Properties
- Material Grades: Available in austenitic (304, 304L, 316, 316L), duplex (2205, 2507), and custom alloy grades to meet diverse application requirements.
- Surface Finish: Bright annealed (BA), pickled and passivated (2B), or custom polished finishes available.
- Microstructure: Uniform austenitic or duplex microstructure providing excellent corrosion resistance, formability, and mechanical integrity.
- Mechanical Properties: Optimized yield strength and elongation for consistent bending behavior with minimal springback variation.
- Corrosion Resistance: Superior resistance to pitting, crevice, and intergranular corrosion, particularly in 316-series and duplex grades.
Specifications
| Parameter | Specification |
|---|---|
| Tube Form | Coil (continuous coil supply) |
| Outer Diameter (OD) | 6.0 mm – 25.4 mm (custom sizes available) |
| Wall Thickness | 0.5 mm – 2.0 mm |
| Coil Inner Diameter | 100 mm – 200 mm |
| Coil Outer Diameter | Up to 600 mm |
| Straightness (Deviation per Unit Length) | ≤ 1.0 mm/m (typical); ≤ 0.5 mm/m (premium grade) |
| Roundness (Ovality) | ≤ 5% of nominal OD |
| OD Tolerance | ± 0.05 mm – ± 0.10 mm |
| Wall Thickness Tolerance | ± 10% of nominal |
| Material Grades | 304, 304L, 316, 316L, 2205, 2507, Custom |
| Coil Weight | Up to 2,000 kg per coil |
Manufacturing Process
The production of high-precision stainless steel coil tube follows a rigorous multi-stage manufacturing process:
- Strip Selection: Cold-rolled stainless steel strip is sourced from certified mills with verified chemical composition and mechanical properties.
- Forming & Welding: Precision roll-forming and TIG/argon welding (or seamless via cold drawing) produce uniform tube geometry with minimal residual stress.
- Coiling: Tubes are wound onto precision coils under controlled tension to minimize permanent set and ensure uniform coil geometry.
- Heat Treatment: Solution annealing or stress-relief annealing eliminates residual stresses, optimizing the tube's natural straightening capability upon unwinding.
- Straightness Calibration: Each coil undergoes post-unwinding straightness measurement, with deviation per unit length (mm/m) recorded and verified against tolerance specifications.
- Surface Treatment: Pickling, passivation, or polishing applied as required to ensure corrosion resistance and aesthetic finish.
- Final Inspection & Packaging: Comprehensive dimensional, chemical, and mechanical testing followed by protective packaging for shipment.
Key Quality Control — Straightness & Springback Performance
The defining quality attribute of this coil tube product is its controlled natural straightening behavior upon unwinding. The deviation per unit length (mm/m) is meticulously measured and documented for each coil batch. This parameter directly governs the feeding accuracy of automated bending machines (CNC tube benders, robotic forming stations), ensuring that programmed bend angles and radii are achieved without compensatory adjustments. Wenzhou Jixing maintains springback deviation within ±0.5 mm/m for premium grades, enabling sub-millimeter precision in automated fabrication.
Applications
- Automotive Industry: Precision fuel lines, brake lines, exhaust components, and HVAC refrigerant tubing requiring automated CNC bending.
- Medical Devices: Endoscope sheaths, surgical instrument tubing, and implant-grade components demanding ultra-tight dimensional control.
- Food & Beverage Processing: Sanitary-grade piping, heat exchanger coils, and hygienic transfer lines.
- Oil & Gas: Downhole tubing, instrumentation lines, and high-pressure fluid conveyance systems.
- Electronics & Semiconductors: Precision heat transfer tubes, vacuum chamber components, and cryogenic applications.
- Aerospace: Hydraulic lines, fuel system tubing, and structural components with stringent springback requirements.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001 — Environmental Management System
- EN 10204 3.1 — Material Test Certificate compliance
- ASTM / ASME — Material and dimensional standards adherence
- CE Marking — European conformity for pressure equipment directives
- Mill Test Reports (MTR) — Full chemical and mechanical analysis provided per batch
- Third-Party Inspection — Available upon request (SGS, Bureau Veritas, TUV)
Unique Selling Points
- Quantified Straightness Guarantee: Each coil is tested and certified with documented deviation per unit length (mm/m), eliminating guesswork in automated processing.
- Reduced Scrap Rates: Predictable springback behavior minimizes rework and material waste in CNC bending operations.
- Continuous Supply Advantage: Coil format enables uninterrupted automated production, reducing changeover time and maximizing throughput.
- Multi-Grade Availability: Broad material selection from standard austenitic to high-performance duplex and custom alloys.
- End-to-End Traceability: Full batch traceability from raw strip through final coil, supporting regulatory compliance in medical, aerospace, and food industries.
- Custom Engineering Support: Wenzhou Jixing provides tailored springback specifications and tolerance engineering for specialized applications.
Wenzhou Jixing Metal Materials Co., Ltd. is committed to delivering stainless steel coil tube products that meet the most demanding precision manufacturing requirements. Our expertise in straightness control and springback management positions us as a trusted supplier for automated tube processing applications worldwide.