Stainless Steel Coil Tube (Coiltube) — Wenzhou Jixing Metal Materials Co., Ltd
Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered, cold-formed tubing product supplied in continuous coil configuration. Manufactured by Wenzhou Jixing Metal Materials Co., Ltd, this product is designed for versatile industrial applications including cable sheathing, structural reinforcement, fluid conveyance, and mechanical component fabrication. The coil form factor enables continuous feeding into downstream processing equipment — such as twisting machines, extruders, and cutting stations — thereby maximizing production efficiency and minimizing material waste.
The product is particularly suited for cable manufacturing operations, including the production of multi-core filled cables (e.g., four-core hemp-filled cables) using multi-coil tube twisting machines. Its inherent mechanical properties, corrosion resistance, and dimensional consistency make it a critical raw material in wire and cable industries, as well as in general engineering applications.
Material & Properties
The Stainless Steel Coil Tube is fabricated from high-grade austenitic stainless steel grades, most commonly 304 (UNS S30400), 304L (UNS S30403), and 316L (UNS S31603). These grades provide an optimal balance of mechanical strength, formability, and resistance to oxidation and chemical attack.
- Chemical Composition (Typical — Grade 304): Carbon (C) ≤ 0.08%, Manganese (Mn) ≤ 2.0%, Chromium (Cr) 18.0–20.0%, Nickel (Ni) 8.0–10.5%, Silicon (Si) ≤ 1.0%, Phosphorus (P) ≤ 0.045%, Sulfur (S) ≤ 0.030%
- Chemical Composition (Typical — Grade 316L): Carbon (C) ≤ 0.030%, Manganese (Mn) ≤ 2.0%, Chromium (Cr) 16.0–18.0%, Nickel (Ni) 10.0–14.5%, Molybdenum (Mo) 2.0–3.0%
- Tensile Strength: ≥ 515 MPa (annealed condition)
- Yield Strength: ≥ 205 MPa
- Elongation at Break: ≥ 40%
- Hardness: ≤ 92 HRB (annealed)
- Corrosion Resistance: Excellent resistance to atmospheric, acidic, and alkaline environments; 316L grade offers superior resistance to pitting and crevice corrosion due to molybdenum addition
- Formability: High ductility allows cold bending, deep drawing, and coiling without cracking or work-hardening failure
- Temperature Range: Continuous service from cryogenic temperatures (−196°C) up to 870°C (oxidation resistance limits)
Specifications
| Parameter | Specification / Range | Standard Reference |
|---|---|---|
| Product Name | Stainless Steel Coil Tube (Coiltube) | — |
| Material Grades | 304, 304L, 316L, 321, 310S (custom grades available) | ASTM A269 / ASME SA-269 |
| Outer Diameter (OD) | 3.0 mm – 50.8 mm (custom sizes upon request) | EN 10217-7 / GB/T 12771 |
| Wall Thickness | 0.3 mm – 3.0 mm | ASTM A269 |
| Coil Inner Diameter | 100 mm – 300 mm | — |
| Coil Weight | 50 kg – 500 kg per coil | — |
| Surface Finish | 2B (cold rolled & annealed), BA (Bright Annealed), No. 4 Brushed, Mirror (8K) | ASTM A480 / GB/T 4237 |
| Tolerance (OD) | ± 0.05 mm – ± 0.10 mm | ASTM A269 |
| Tolerance (Wall Thickness) | ± 10% of nominal | ASTM A269 |
| Weld Seam | Continuous welded (ERW / Laser welded) or seamless | ASTM A554 / ISO 14343 |
| Heat Treatment | Annealed (solution annealed at 1040–1120°C, water or air quenched) | — |
| Coil Packaging | Wooden pallet with stretch film wrapping and steel banding | — |
| Applicable Standards | ASTM A269, ASME SA-269, EN 10217-7, GB/T 12771, JIS G3446 | — |
Manufacturing Process
The production of the Stainless Steel Coil Tube follows a rigorous multi-stage manufacturing sequence designed to ensure dimensional accuracy, metallurgical integrity, and surface quality:
- Raw Material Preparation: Stainless steel strip (coil form) is sourced from certified mills, meeting the specified chemical composition and mechanical properties. Incoming material undergoes spectrographic verification.
- Strip Cleaning & Surface Preparation: The strip is degreased and pickled to remove scale, oxides, and contaminants prior to forming.
- Tube Forming (Roll Forming): The flat strip is fed through a series of progressive rollers that progressively bend and shape the strip into a tubular cross-section. This cold-forming process preserves the metallurgical properties of the base material.
- Welding: A continuous longitudinal weld is formed using either Electric Resistance Welding (ERW) or high-precision laser welding. Laser welding produces a narrow heat-affected zone (HAZ) with minimal distortion.
- Internal & External Finishing: The weld seam is dressed using internal and external grinding or brushing tools to achieve uniform wall thickness and smooth surface finish.
- Dimensional Calibration: The tube passes through sizing rolls or mandrel stations to achieve precise outer diameter and wall thickness tolerances.
- Solution Annealing: The formed tube is heat-treated at 1040–1120°C followed by rapid quenching (water or controlled air) to relieve residual stresses, restore full ductility, and achieve the desired corrosion-resistant microstructure.
- Pickling & Passivation: Post-annealing surface oxides are removed via acid pickling, followed by passivation treatment to form a protective chromium oxide layer.
- Coiling: The continuous tube is wound onto a coil reel in the desired inner diameter configuration. Coil tension is controlled to prevent deformation or kinking.
- Quality Inspection & Packaging: Each coil undergoes dimensional measurement, surface inspection, and (where applicable) hydrostatic testing. Approved coils are packaged for shipment.
Applications
The Stainless Steel Coil Tube finds extensive application across multiple industrial sectors:
- Wire & Cable Industry: Used as protective sheathing for multi-core cables, including four-core hemp-filled cables produced on multi-coil tube twisting machines. The coil form enables continuous feeding into cable extrusion and twisting equipment.
- Food & Beverage Processing: Tubing for conveying sanitary-grade fluids, beverage lines, and dairy processing equipment (304/316L grades).
- Pharmaceutical Equipment: Hygienic piping systems requiring cleanability and resistance to chemical sterilants.
- Chemical Processing: Corrosion-resistant tubing for aggressive chemical environments, particularly with 316L grade.
- Automotive & Aerospace: Exhaust systems, fuel lines, and structural tubing components.
- Construction & Architectural: Structural bracing, handrails, and decorative elements.
- Medical Devices: Surgical instrument tubing, endoscope sheaths, and implantable device housings.
- Mechanical Engineering: Hydraulic lines, pneumatic tubing, and precision mechanical assemblies.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management framework ensuring that all Stainless Steel Coil Tube products meet international standards:
- ISO 9001:2015 — Quality Management System Certification
- ISO 14001:2015 — Environmental Management System Certification
- ASTM A269 / ASME SA-269 Compliance — Specification for welded austenitic stainless steel tubing
- EN 10217-7 Compliance — European standard for austenitic stainless steel tubing
- GB/T 12771 Compliance — Chinese national standard for welded stainless steel tubing
- Mill Test Certificates (MTC) — EN 10204 Type 3.1 certificates provided with each shipment
- Third-Party Inspection — Available upon customer request (SGS, Bureau Veritas, Intertek)
Unique Selling Points
- Continuous Coil Configuration: Eliminates joint discontinuities and enables seamless integration with automated downstream processing equipment, significantly improving manufacturing throughput.
- Precision Dimensional Control: Tight tolerances on outer diameter and wall thickness ensure interchangeability and fit-for-purpose performance in critical applications.
- Superior Surface Quality: Multiple surface finish options (2B, BA, brushed, mirror) accommodate diverse aesthetic and functional requirements.
- Multi-Grade Availability: Comprehensive range of stainless steel grades including 304, 304L, 316L, 321, and 310S, covering atmospheric through to high-temperature and highly corrosive environments.
- Optimized for Cable Manufacturing: Specifically suited for use in multi-coil tube twisting operations, including four-core filled cable production, where consistent tube geometry and reliable weld integrity are paramount.
- Full Traceability: Each coil is traceable to its mill heat number, ensuring complete supply chain accountability.
- Custom Fabrication Capability: Non-standard dimensions, surface treatments, and coil configurations available upon request to meet specialized customer requirements.
Note: All specifications listed are representative values. Actual product characteristics may vary based on grade selection, manufacturing batch, and customer-specific requirements. Prospective purchasers are advised to provide detailed application parameters to receive a customized quotation and technical recommendation from Wenzhou Jixing Metal Materials Co., Ltd.