Stainless Steel Coil Tube — Non-Standard & Extreme Specification Series
Product Overview
The Non-Standard and Extreme Specification Coil Tube series, produced by Wenzhou Jixing Metal Materials Co., Ltd, represents a specialized segment of stainless steel tubing engineered for applications demanding dimensions that fall outside conventional manufacturing tolerances. This product line encompasses ultra-thin wall tubing (wall thickness below 0.5 mm), ultra-thick wall tubing (wall thickness exceeding 3.0 mm), and tubing with non-standard outer diameters (OD) that deviate from industry-standard sizing conventions.
Due to the inherent manufacturing challenges associated with these extreme dimensional parameters — including significantly reduced material yield rates, elevated defect susceptibility, and the necessity for frequent die changes — the Non-Standard and Extreme Specification series carries a premium surcharge ranging from 10% to 30% above standard pricing. This surcharge reflects the additional process complexity, specialized tooling requirements, and extended production cycle times intrinsic to these products.
Material & Properties
Coil tubes in this series are manufactured from high-grade austenitic and ferritic stainless steel grades, selected to ensure optimal formability, corrosion resistance, and mechanical integrity across the full range of wall thickness extremes.
- Base Materials: AISI 304, AISI 316L, AISI 321, AISI 310S, AISI 430, and custom alloy compositions
- Corrosion Resistance: Superior resistance to pitting, crevice corrosion, and intergranular corrosion in aggressive environments
- Mechanical Properties: Tensile strength ranging from 520 to 950 MPa depending on grade and temper condition; elongation exceeding 30% for austenitic grades
- Temperature Performance: Operating temperature range from cryogenic (−196°C) to 870°C (304/321 grades) and up to 1150°C (310S grade)
- Surface Finish: Available in No.1 annealed, 2B cold-rolled, BA (Bright Annealed), and custom polished finishes
Specifications
| Parameter | Standard Range | Non-Standard / Extreme Range | Premium Surcharge |
|---|---|---|---|
| Wall Thickness (Ultra-Thin) | 0.5 – 1.0 mm | < 0.5 mm (down to 0.1 mm) | 15% – 30% |
| Wall Thickness (Ultra-Thick) | 1.0 – 3.0 mm | > 3.0 mm (up to 12.7 mm) | 10% – 25% |
| Outer Diameter (OD) — Non-Standard | Industry-standard increments | Custom OD per customer specification | 10% – 20% |
| Material Yield Rate | 75% – 85% | 40% – 65% | — |
| Die Change Frequency | Standard die set | High frequency — custom die fabrication required | — |
| Coil Length | 3 – 6 m per coil | Custom lengths available | 5% – 10% |
| Tolerance — OD | ±0.1 mm | ±0.05 mm (ultra-precise) | 10% – 15% |
| Tolerance — Wall Thickness | ±10% | ±5% (tight tolerance) | 10% – 20% |
Manufacturing Process
The production of non-standard and extreme specification coil tubes involves a multi-stage process with significantly elevated complexity compared to standard tubing manufacture:
- Raw Material Preparation: High-purity stainless steel strip is sourced from certified mills and undergoes rigorous incoming inspection for chemical composition, mechanical properties, and surface condition.
- Coiling and Forming: The strip is fed into a coiling machine where it is wound into a continuous helical coil shape. For ultra-thin wall tubing, specialized low-force forming heads and precision tension control systems are employed to prevent material deformation and tearing.
- Welding: A continuous TIG (Tungsten Inert Gas) welding process is utilized to create the longitudinal seam. For extreme wall thickness variants, multi-pass welding with precise heat input management ensures full penetration and minimizes residual stress.
- Post-Weld Annealing: The welded coil tube undergoes solution annealing in a controlled atmosphere furnace to restore mechanical properties, relieve residual stresses, and stabilize the microstructure.
- Surface Treatment: Pickling and passivation processes are applied to remove oxide scale and establish a protective chromium oxide film, ensuring optimal corrosion resistance.
- Dimensional Inspection: Each coil undergoes 100% dimensional verification using laser measurement systems, with statistical process control (SPC) monitoring to maintain tight tolerances.
- Coil Packaging: Finished coils are wound onto precision-machined cores, wrapped in protective film, and secured with steel strapping for safe handling and transportation.
Key Manufacturing Challenges: The non-standard and extreme specification series demands significantly more frequent die changes and custom tooling fabrication, which directly contributes to the 10%–30% premium surcharge. The material yield rate is substantially reduced — often falling to 40%–65% compared to 75%–85% for standard products — due to increased edge waste, higher rejection rates, and the need for conservative cutting tolerances.
Applications
Non-standard and extreme specification stainless steel coil tubes are deployed in demanding industrial applications where standard dimensions are insufficient:
- Ultra-Thin Wall (<0.5 mm): Medical device tubing, pharmaceutical processing lines, analytical instrumentation, precision fluidic systems, and aerospace fuel lines
- Ultra-Thick Wall (>3.0 mm): High-pressure hydraulic systems, heavy-duty structural applications, pressure vessel components, and industrial heat exchanger tubes
- Non-Standard OD: Custom-fit replacement tubing for legacy equipment, specialized OEM assemblies, and unique architectural or artistic installations
- Cross-Industry Use: Automotive exhaust systems, food processing equipment, chemical processing plants, semiconductor manufacturing, and nuclear power applications
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd maintains comprehensive quality management systems to ensure consistent product performance across all specification ranges:
- ISO 9001:2015 — Quality Management System certification covering all manufacturing and inspection processes
- ISO 14001:2015 — Environmental Management System certification demonstrating commitment to sustainable manufacturing practices
- ISO/IEC 17025 — Laboratory competence certification for in-house testing and measurement facilities
- ASME / PED — Compliance with pressure equipment directives for high-pressure application tubing
- Material Traceability: Full mill certificate traceability from raw material to finished product, including chemical analysis, mechanical test reports, and dimensional verification records
- NDT (Non-Destructive Testing): Available upon request — including eddy current testing, ultrasonic testing, and helium leak testing for seam integrity verification
Unique Selling Points
- Extreme Dimensional Flexibility: Capability to manufacture wall thicknesses from 0.1 mm to 12.7 mm and custom outer diameters beyond standard catalog offerings, addressing niche market demands that standard manufacturers cannot accommodate
- Transparent Premium Pricing: Clear, well-defined surcharge structure (10%–30%) based on measurable production complexity factors — material yield rate reduction and die change frequency — ensuring pricing transparency for procurement teams
- End-to-End Customization: From raw material selection through final coil packaging, every production parameter can be tailored to specific customer requirements with dedicated engineering support
- Comprehensive Quality Assurance: Multi-stage inspection protocols with full material traceability, ensuring that even extreme specification products meet rigorous dimensional and metallurgical standards
- Reduced Lead Times for Special Orders: Optimized production scheduling and dedicated tooling inventory minimize turnaround times for non-standard orders compared to typical custom manufacturing lead times
Procurement Note: The 10%–30% specification surcharge for non-standard and extreme specification coil tubes is an industry-standard practice reflecting genuine production cost increases. This premium encompasses reduced material yield rates (40%–65% vs. 75%–85% standard), frequent die changes requiring custom tooling fabrication, extended setup and changeover times, and elevated quality control inspection requirements. Customers are advised to provide detailed dimensional specifications and quantity forecasts during the quotation stage to optimize pricing and minimize surcharge exposure.