Stainless Steel Coil Tube — Precision-Wound Heat Transfer Tubing with Dynamic Alloy Pricing
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. supplies high-performance stainless steel coil tubes engineered for demanding thermal exchange and fluid handling applications. Coil tubes are manufactured by cold-drawing seamless or welded stainless steel tubing and precision-winding it into a continuous coil configuration, delivering uniform geometry, minimal material waste, and superior thermal efficiency. These coils are the backbone of modern heat exchangers, condensers, evaporators, and refrigeration systems across global industrial sectors.
A defining feature of this product line is its dynamic pricing architecture, which directly links contract pricing to live commodity metal markets. This ensures buyers receive cost-competitive material while suppliers maintain sustainable margins — a transparent mechanism built on industry-leading alloy cost transparency.
Unique Selling Points
- LME-Linked Transparent Pricing: Contract pricing is anchored to a locked base price plus a transparent alloy surcharge formula, ensuring both parties share the risk and reward of fluctuating metal markets.
- Multi-Grade Availability: Supply covers the full stainless steel spectrum — from standard austenitic grades (304, 304L, 316, 316L) to super-austenitic (904L, 254 SMO) and duplex (2205, 2507) alloys.
- Precision Coil Geometry: Tightly controlled coil diameter tolerances (±0.5 mm) and tube straightness ensure seamless integration into automated coil-winding machinery.
- Full Traceability: Every coil lot is traceable from raw mill ingot through final inspection, with complete material certificates and heat-number documentation.
Material & Properties
Available Grades
The coil tube product line accommodates a broad range of stainless steel grades to match specific corrosion, temperature, and mechanical requirements:
- 304 / 304L (UNS S30400 / S30403): General-purpose austenitic grade with excellent formability and corrosion resistance in mild environments.
- 316 / 316L (UNS S31600 / S31603): Molybdenum-enhanced austenitic grade offering superior resistance to chlorides, acids, and marine environments.
- 321 (UNS S32100): Titanium-stabilized grade with enhanced resistance to intergranular corrosion at elevated temperatures.
- 904L (UNS N08904): High-alloy super-austenitic grade for severe oxidizing and reducing acid environments.
- 254 SMO (UNS S31803): Ultra-high alloy austenitic grade for extreme chloride pitting and crevice corrosion resistance.
- 2205 Duplex (UNS S32205): High-strength duplex grade combining corrosion resistance with roughly double the yield strength of 304L.
- 2507 Super Duplex (UNS S32750): Maximum-strength duplex for offshore, oil & gas, and chemical processing applications.
Key Mechanical Properties (Typical — Grade 316L)
- Tensile Strength: ≥ 485 MPa (≥ 70 ksi)
- Yield Strength (0.2% offset): ≥ 205 MPa (≥ 30 ksi)
- Elongation: ≥ 40% (minimum, 50 mm gauge length)
- Hardness: ≤ 230 HB (Brinell)
- Operating Temperature Range: −196 °C to +425 °C (−321 °F to +797 °F)
Key Chemical Composition (Typical — Grade 316L)
| Element | Minimum (%) | Maximum (%) |
|---|---|---|
| Carbon (C) | — | 0.030 |
| Chromium (Cr) | 16.0 | 18.0 |
| Nickel (Ni) | 10.0 | 14.0 |
| Molybdenum (Mo) | 2.0 | 3.0 |
| Manganese (Mn) | — | 2.0 |
| Silicon (Si) | — | 1.0 |
| Phosphorus (P) | — | 0.035 |
| Sulfur (S) | — | 0.030 |
Specifications
| Parameter | Specification |
|---|---|
| Product Form | Continuous Coil Tube (盘管 / Coil Tube) |
| Tube Outer Diameter (OD) | 3.18 mm – 38.10 mm (1/8" – 1-1/2") |
| Tube Wall Thickness | 0.25 mm – 3.00 mm (0.0098" – 0.1181") |
| Coil Outer Diameter | 150 mm – 800 mm (5.9" – 31.5") |
| Coil Inner Diameter | 50 mm – 250 mm (2.0" – 9.8") |
| Coil Length (per coil) | 100 m – 5,000 m (328 ft – 16,404 ft), configurable |
| OD Tolerance | ±0.05 mm (±0.002") |
| Wall Thickness Tolerance | ±10% of nominal |
| Coil Diameter Tolerance | ±0.5 mm (±0.02") |
| Surface Finish | Bright Annealed, Pickled, or Polished (RA/PK/Polished) |
| Manufacturing Method | Seamless (cold-drawn) or ERW Welded |
| Applicable Standards | ASTM A213, ASTM A269, EN 10216-5, GB/T 14976, JIS G3459 |
| Packaging | Wooden pallet / steel crate, moisture-proof wrapping, export-grade |
| Minimum Order Quantity | 1 ton per grade (configurable for custom orders) |
Manufacturing Process
Each coil tube is produced through a rigorously controlled multi-stage manufacturing workflow:
- Raw Material Selection: Certified stainless steel bar stock or seamless pipe blanks are selected from approved mills, with full chemical analysis and heat-number traceability verified prior to processing.
- Cold Drawing / Piercing: Billet material is cold-drawn through precision tungsten carbide dies to achieve the target tube outer diameter and wall thickness with tight dimensional tolerances.
- Intermediate Annealing: Drawn tubes are solution-annealed at 1,050 °C – 1,100 °C (1,922 °F – 2,012 °F) followed by controlled cooling to restore ductility and relieve cold-work stresses.
- Surface Treatment: Tubes undergo pickling and passivation (or bright annealing in a controlled-atmosphere furnace) to remove oxide scale and establish a protective chromium oxide film.
- Coil Winding: The finished tube is precision-wound onto a steel mandrel using CNC-controlled winding machinery. Tension, speed, and coil diameter are continuously monitored to ensure uniform layer-to-layer stacking and no inter-coil contact damage.
- Final Inspection: Each coil undergoes dimensional verification, surface inspection, hydrostatic pressure testing (where applicable), and optional spectroscopic chemical analysis.
- Packaging & Dispatch: Coils are wrapped in moisture-proof film, secured on wooden pallets or in steel crates, and prepared for export or domestic delivery.
Applications
Wenzhou Jixing's stainless steel coil tubes serve a wide array of industrial and commercial applications:
- Heat Exchangers & Condensers: Spiral-wound coil heat exchangers for HVAC, refrigeration, and industrial process cooling.
- Evaporators & Boilers: Coil-type evaporator tubes in dairy, food processing, and chemical plant equipment.
- Refrigeration & Air Conditioning: Evaporator and condenser coils in commercial refrigeration units, chillers, and heat pumps.
- Automotive Industry: Fuel system tubing, brake lines, and heat exchanger coils for passenger and commercial vehicles.
- Medical Devices: Tubing for medical gas delivery systems, infusion pumps, and laboratory instrumentation.
- Food & Beverage Processing: Sanitary-grade tubing for dairy pasteurizers, brewing systems, and pharmaceutical equipment.
- Petrochemical & Oil/Gas: Corrosion-resistant tubing for offshore platforms, subsea manifolds, and chemical processing units.
- Power Generation: Condenser tubes and heat recovery coils in power plants and cogeneration systems.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework to ensure every coil tube shipment meets international standards:
- ISO 9001:2015 — Quality Management System certification
- ISO 14001:2015 — Environmental Management System certification
- CE Marking — Conformity with European health, safety, and environmental protection standards
- EN 10204 3.1 Certificates — Third-party material test certificates provided with every shipment
- Mill Test Reports (MTR) — Full chemical composition and mechanical property reports traceable to original mill heat numbers
- API Compliance — Available for oil and gas industry applications (upon request)
- NACE MR0175 / ISO 15156 — Compliance for sour service environments (duplex and super-austenitic grades)
Pricing & Commercial Framework
Ni / Mo / Cr Linked Dynamic Pricing Model
Recognizing that the cost of stainless steel is fundamentally driven by the market prices of its core alloying elements — Nickel (Ni), Molybdenum (Mo), and Chromium (Cr) — Wenzhou Jixing implements a transparent and equitable pricing mechanism:
Contract Pricing Formula:
Final Unit Price = Locked Base Price + Alloy Surcharge
Where: Alloy Surcharge = f(LME Monthly Average Prices of Ni, Mo, Cr)
- Locked Base Price: Fixed at contract signing, covering manufacturing, processing, overhead, and profit components.
- Alloy Surcharge: Calculated based on the LME (London Metal Exchange) monthly average prices for the relevant alloying metals, adjusted by a pre-agreed conversion coefficient.
- Adjustment Frequency: Monthly, aligned with LME monthly average publication cycles.
- Transparency: Buyers receive full disclosure of the surcharge calculation formula and component weights at contract execution.
This pricing architecture protects both buyer and seller from volatile commodity market swings, ensuring long-term supply relationship stability while maintaining competitive market pricing. It is particularly advantageous for high-Ni and high-Mo grades (316L, 904L, 254 SMO, 2507) where metal content costs constitute a dominant share of the total price.
Ordering & Customization
Wenzhou Jixing Metal Materials Co., Ltd. offers flexible customization for non-standard requirements including:
- Custom tube OD and wall thickness combinations
- Special coil diameter and length configurations
- Custom surface finishes (polished, hairline, satin)
- Special packaging for export or hazardous environments
- Batch-specific chemical analysis and mechanical testing
For detailed quotations, sample requests, or technical consultations, contact Wenzhou Jixing Metal Materials Co., Ltd. directly. Our engineering team provides responsive support from specification selection through post-delivery quality assurance.