Stainless Steel Coil Tube with Superior Tensile Strength (Rm) Performance
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. presents a premium-grade stainless steel coil tube engineered for demanding industrial applications where exceptional mechanical integrity and structural reliability are paramount. This coiled tubing product is distinguished by its outstanding tensile strength (Rm) characteristics — the maximum load-bearing capacity before fracture — offering performance that sets it apart in the competitive stainless steel tubing market.
The coil tube is manufactured to precise dimensional tolerances and delivered in continuous coil form, facilitating efficient downstream processing including straightening, cutting, bending, and forming. Whether supplied in soft (annealed) temper or hard temper, the product delivers predictable and consistent mechanical behavior, making it an ideal choice for high-performance engineering solutions.
Material & Properties
Tensile Strength (Rm) — The Defining Advantage
Tensile strength (Rm) represents the maximum stress a material can withstand before fracture. This is the critical mechanical property that determines the load-bearing limit of the tubing in service. Wenzhou Jixing's stainless steel coil tube is available in multiple temper conditions:
- Soft (Annealed) Temper: Provides excellent formability and ductility for applications requiring extensive cold working, bending, or shaping after delivery.
- Hard (Cold-Worked) Temper: Achieves tensile strength values reaching 1.5 to 2 times that of the soft temper condition, delivering exceptional resistance to deformation under load.
The direct correlation between hardness state and tensile strength allows engineers to select the optimal temper for their specific application — balancing strength requirements against formability needs. This versatility makes the product suitable for a wide spectrum of industrial uses.
General Material Characteristics
- Corrosion resistance conforming to applicable stainless steel grade standards
- Consistent microstructural uniformity throughout the coil length
- Smooth surface finish with minimal oxide scale for downstream welding and coating
- Compliant with international metallurgical standards for austenitic and/or duplex stainless steel grades
Specifications
| Parameter | Specification | Notes |
|---|---|---|
| Product Type | Stainless Steel Coil Tube | Continuous coil delivery |
| Tensile Strength — Soft Temper (Rm) | ≥ 520 MPa (75,400 psi) | Annealed condition |
| Tensile Strength — Hard Temper (Rm) | 780 – 1,040 MPa (113,100 – 150,800 psi) | 1.5–2× soft temper values |
| Yield Strength (Rp0.2) | 205 – 700 MPa (29,700 – 101,500 psi) | Depends on temper condition |
| Elongation (A50mm) | 30 – 60% (soft); 10 – 25% (hard) | Ductility inversely proportional to strength |
| Outer Diameter | 3.0 – 30.0 mm (0.118 – 1.181 in) | Custom sizes available |
| Wall Thickness | 0.3 – 3.0 mm (0.012 – 0.118 in) | Tolerance ±10% |
| Coil Inner Diameter | 500 – 600 mm (19.7 – 23.6 in) | Standard packaging |
| Coil Length | 50 – 200 m (164 – 656 ft) | Variable per order |
| Surface Finish | Bright Annealed / Pickled / Polished | As specified |
| Applicable Grades | 304, 304L, 316, 316L, 321, 310S, Duplex 2205 | Custom grades on request |
| Standards Compliance | ASTM A269, ASTM A213, EN 10217, GB/T 12771 | Mutually exclusive per order |
Manufacturing Process
- Raw Material Selection: High-purity stainless steel billets or strip are sourced from certified mills, with incoming inspection verifying chemical composition and metallurgical quality.
- Piercing and Forming: Hot-rolled tube blanks are drawn through sequential dies to achieve target outer diameter and wall thickness, or seamless tube is produced via rotary piercing methods.
- Cold Drawing: Precision cold drawing through calibrated dies reduces dimensions to final specification while enhancing mechanical properties through work hardening.
- Temper Control: The final temper (soft or hard) is achieved through controlled heat treatment (annealing) or sustained cold working, respectively. Hard temper products undergo extensive cold reduction to maximize tensile strength.
- Surface Treatment: Bright annealing in protective atmosphere eliminates scale and restores corrosion resistance while maintaining dimensional accuracy.
- Coiling: Finished tubing is wound into coils on precision-controlled pay-off reels, with tension monitoring to prevent deformation or kinking.
- Quality Inspection: Each coil undergoes dimensional verification, mechanical testing (including Rm determination per ASTM E8), and visual surface inspection prior to packaging.
Applications
The combination of superior tensile strength, corrosion resistance, and coil-form convenience makes this product suitable for a broad range of high-performance applications:
- Heat Exchangers and Boilers: Hard-temper tubing withstands thermal cycling and pressure differentials in power generation and process heat exchange systems.
- Automotive Exhaust Systems: High tensile strength resists vibration fatigue and thermal degradation in exhaust manifold and tailpipe assemblies.
- Precision Instrumentation: Soft-temper tubing is drawn and formed into precision capillaries for pressure gauges, thermometers, and analytical instruments.
- Medical Devices: Biocompatible grades in annealed condition are used for surgical instruments, implant components, and diagnostic equipment housings.
- Fluid Conveyance Systems: Coil form enables efficient fabrication of complex piping networks in chemical processing, food & beverage, and pharmaceutical plants.
- Structural Components: Hard-temper tubing serves as reinforcement elements in aerospace, marine, and heavy machinery where weight-to-strength ratio is critical.
- Wire Drawing Feedstock: Coil tube is readily processed into precision wire for springs, fasteners, and electrical components.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains rigorous quality management systems and holds the following certifications:
- ISO 9001:2015 — Quality Management System certification ensuring consistent production standards
- ISO 14001 — Environmental Management System compliance
- EN 10204 3.1 Certificates — Third-party material test certificates available for all shipments
- PED Compliance — Pressure Equipment Directive conformity for applicable products
- Mill Test Reports (MTR) — Comprehensive chemical and mechanical analysis documentation per heat number
Unique Selling Point: The availability of hard-temper coil tube with tensile strength (Rm) reaching 1.5 to 2 times the soft-temper baseline provides engineers with a single supplier solution for both high-strength and high-formability requirements. This dual-temper capability, combined with precise coil-form delivery, eliminates the need for multiple suppliers and reduces supply chain complexity while ensuring mechanical property traceability from mill to end application.
Wenzhou Jixing Metal Materials Co., Ltd. is committed to delivering stainless steel coil tube products that meet the most demanding engineering specifications, backed by full traceability, certified quality, and technical support throughout the project lifecycle.