Precision-Grade Stainless Steel Coil Tube — Ultra-Tight Tolerance OD±0.5%, WT±5%

Product Overview

The Precision-Grade Stainless Steel Coil Tube from Wenzhou Jixing Metal Materials Co., Ltd. is engineered to deliver exceptionally tight dimensional tolerances that meet the most demanding requirements in high-precision assembly and fluid handling applications. With an outer diameter (OD) tolerance of ±0.5% and a wall thickness (WT) tolerance of ±5%, this product represents the highest precision grade available in the coil tube category, making it an indispensable choice for industries where dimensional consistency is non-negotiable.

Unlike standard or commercial-grade coil tubes, the precision grade ensures uniformity across the entire coil length, enabling reliable cold-forming, consistent fitment with cartridge (compression) fittings, and seamless integration into automated assembly lines. This product is the definitive solution for OEMs and system integrators who require zero-compromise dimensional accuracy.

Unique Selling Points

• Industry-Leading Tolerance: OD tolerance of ±0.5% and wall thickness tolerance of ±5% — significantly tighter than commercial (±5% OD, ±10% WT) or high-quality (±1% OD, ±5% WT) grades.
• Cartridge Fitting Ready: The ultra-tight dimensional control ensures perfect engagement with cartridge (compression) fittings, eliminating leakage risks and reducing assembly time.
• Coil Format Efficiency: Delivered in continuous coil form to maximize material utilization, minimize cutting waste, and enable high-speed automated forming and fabrication.
• Full Traceability: Each coil is heat-number traceable with complete mill test certificates, supporting compliance with stringent regulatory and quality management systems.
• Multi-Grade Availability: Available in 304, 304L, 316, 316L, 321, 310S, and custom alloy specifications to match application-specific corrosion and mechanical requirements.

Material & Properties

Available Grades

• Austenitic: 304 (1.4301), 304L (1.4307), 316 (1.4401), 316L (1.4404), 321 (1.4541), 310S (1.4845)
• Custom Alloys: 2205 Duplex, 904L, Hastelloy C-276, Inconel 625 — upon request

Key Mechanical Properties (Typical — 304/304L Grade)

• Tensile Strength: ≥520 MPa (75,400 psi)
• Yield Strength: ≥205 MPa (29,700 psi)
• Elongation: ≥40%
• Hardness: ≤95 HRB (annealed condition)
• Density: 8.0 g/cm³ (0.289 lb/in³)
• Thermal Conductivity: 16.3 W/(m·K) at 100°C
• Operating Temperature Range: −196°C to +870°C (−321°F to +1,598°F)

Surface Finish Options

• Pickled & Passivated: Standard finish, Ra ≤ 1.6 μm
• Pickled & Polished: Ra ≤ 0.8 μm
• Mechanical Polished: Ra ≤ 0.4 μm (available upon request)
• Electro-Polished: Ra ≤ 0.25 μm (for hygienic/pharmaceutical applications)

Specifications

Parameter	Specification	Notes
Product Name	Precision-Grade Stainless Steel Coil Tube	—
Product Category	Coil Tube (盘管)	Continuous coil form
Tolerance Grade	Precision (精密级)	Highest available grade
OD Tolerance	±0.5%	Critical for fitting compatibility
Wall Thickness Tolerance	±5%	Ensures uniform pressure rating
OD Range	3.0 mm – 50.8 mm (0.118" – 2.0")	Custom sizes available
Wall Thickness Range	0.3 mm – 3.0 mm (0.012" – 0.118")	Thin-wall specialization
Coil Length	10 m – 200 m (33 ft – 656 ft)	Configurable per order
Coil Diameter	300 mm – 1,000 mm (11.8" – 39.4")	Standard: 500 mm / 600 mm
Manufacturing Method	Seamless / Precision Drawn	EN 10217-7 compliant
Applicable Standards	EN 10217-7, ASTM A269/A270, ISO 1307	Multi-standard compliance
End Condition	Plain / Beveled / Chamfered	Custom end prep available
Packaging	Wooden crate / Export-grade coil wrap	Moisture-protected

Manufacturing Process

1. Raw Material Selection: Virgin or certified recycled stainless steel billets are sourced from accredited mills with full chemical composition verification via spectroscopic analysis.
2. Hot Rolling & Annealing: Billets are heated to controlled temperatures and hot-rolled into hollow tubes, followed by solution annealing to achieve full austenitic microstructure.
3. Precision Cold Drawing: The tube is cold-drawn through precision-die tooling to achieve the target OD and WT within the ±0.5% / ±5% tolerance envelope. Multiple drawing passes may be employed for thinner wall sections.
4. Intermediate Annealing: Periodic annealing cycles relieve accumulated cold-work stresses and restore ductility between drawing passes.
5. Final Sizing & Straightening: A final precision sizing pass ensures dimensional accuracy is maintained along the full tube length, followed by controlled straightening to eliminate residual curvature.
6. Pickling & Passivation: The tube surface is chemically cleaned via acid pickling to remove scale and oxidation, followed by passivation to form a protective chromium oxide layer.
7. Coiling: The finished tube is wound into coils of specified diameter using automated coiling equipment to prevent surface damage and maintain dimensional integrity.
8. 100% Inspection: Every coil undergoes dimensional verification (OD and WT measured at multiple points), hydrostatic testing, and surface inspection before packaging.

Applications

Primary Use Cases

• Cartridge (Compression) Fitting Systems: The ultra-tight OD and WT tolerances are essential for reliable engagement with cartridge fittings in hydraulic, pneumatic, and fluid transfer systems. Any dimensional deviation can compromise seal integrity — the precision grade eliminates this risk entirely.
• Precision Assembly & Automation: Ideal for automated tube-cutting, bending, and forming operations where consistent dimensions prevent tooling damage and reduce cycle-time variability.
• Hydraulic & Pneumatic Systems: Used in high-pressure fluid conveyance lines where leak-free performance and long service life are critical — automotive, aerospace, and industrial machinery.
• Medical & Pharmaceutical Equipment: Electro-polished precision coil tubes are used in fluid delivery systems, infusion devices, and cleanroom-compatible piping where both dimensional accuracy and surface cleanliness are mandated.
• Semiconductor & Electronics Manufacturing: High-purity gas and chemical delivery lines require precision tubing with verified dimensions and ultra-clean surfaces.
• Food & Beverage Processing: Sanitary-grade precision tubing for CIP (Clean-in-Place) systems, milk lines, and beverage transfer where consistent wall thickness ensures proper flow dynamics.
• Heat Exchangers & Radiators: Precision coil tubes form the core of compact heat exchanger designs where uniform wall thickness ensures consistent thermal performance.

Why Precision Grade Is Mandatory for Cartridge Fittings

Cartridge (compression) fittings rely on the precise interaction between the tube's outer surface and the fitting's internal sealing mechanism. An OD variation exceeding ±1% can result in incomplete seal engagement, leading to micro-leakage, premature fitting failure, and costly system downtime. The Precision Grade at OD±0.5% and WT±5% is not merely preferred — it is mandatory for any application involving cartridge fittings and high-precision assembly where dimensional consistency directly impacts system safety and reliability.

Quality Certifications & Compliance

• ISO 9001:2015 — Quality Management System certification covering the entire supply chain from raw material procurement through final dispatch.
• ISO 13485 — Medical device quality management system (for medical-grade product lines).
• EN 10204 3.1 — Full mill test certificates with third-party inspection available upon request.
• EN 10217-7 — Technical delivery conditions for austenitic stainless steel tubes for pressure purposes.
• ASTM A269 / A270 — Standard specification for seamless and welded austenitic stainless steel tubes for boiler, heat-exchanger, and similar heat-absorbing applications.
• ISO 1307 — Tubes and pipes — Tolerances on dimensions.
• CE Marking — Conformity with European Pressure Equipment Directive (PED 2014/68/EU) where applicable.
• NSF/ANSI 61 — Available for drinking water applications.
• 3-A Sanitary Standards — Available for food and dairy processing applications.

Technical Support & Customization

Wenzhou Jixing Metal Materials Co., Ltd. offers comprehensive technical support including:

• Custom OD and WT dimensions within the precision tolerance envelope
• Special alloy grades and surface finishes tailored to specific application requirements
• Coil configuration optimization (diameter, length, bundling) for customer-specific handling and forming equipment
• Third-party inspection coordination (SGS, Bureau Veritas, Lloyd's) upon request
• Sample provision and tolerance verification prior to bulk order placement

For detailed quotations, technical data sheets, or sample requests, contact Wenzhou Jixing Metal Materials Co., Ltd. directly. Our engineering team is available to assist with material selection, tolerance verification, and application-specific design consultation.