Stainless Steel Coil Tube (盘管) — Product Technical Specification

1. Product Overview

The Stainless Steel Coil Tube, manufactured by Wenzhou Jixing Metal Materials Co., Ltd., is a precision-engineered continuous-length tubular product formed into a helical or spiral coil configuration. Unlike conventional straight stainless steel pipes or seamless tubes, coil tubes are produced through a continuous forming process that yields uninterrupted lengths wound onto industrial spools or coils. This configuration offers superior material utilization, minimal welding requirements in downstream applications, and exceptional flexibility in forming and fabrication workflows.

Coil tubes serve as critical intermediate or finished products across a broad spectrum of industries, including automotive exhaust systems, heat exchanger assemblies, fluid transfer systems, architectural decoration, and specialized pump manufacturing. The coil form factor enables efficient storage, transportation, and on-site processing, making it an economically advantageous alternative to cut-length pipe stock for high-volume manufacturing environments.

2. Material & Properties

Stainless steel coil tubes are fabricated from austenitic, ferritic, or duplex stainless steel grades, selected according to the specific mechanical, corrosion resistance, and temperature performance requirements of the target application.

2.1 Common Material Grades

2.2 Key Mechanical Properties (Typical Values for Grade 304)

3. Technical Specifications

Parameter Specification Standard / Reference
Outer Diameter (OD) Range 3.175 mm – 304.8 mm (⅛" – 12") ASTM A554, EN 10217
Wall Thickness Range 0.1 mm – 10 mm (0.004" – 0.394") ASTM A554, GB/T 14976
Coil Inner Diameter (Coil ID) 150 mm – 600 mm (6" – 24") Custom / Customer Specified
Coil Length per Spool 50 m – 1,000 m (164 ft – 3,281 ft) Custom / Customer Specified
Surface Finish Options 2B, BA (Bright Annealed), No.4 Brushed, No.8 Mirror, Sandblasted ASTM A480, EN 10088
Surface Roughness (Ra) 0.05 μm (Mirror) – 1.6 μm (2B Finish) ISO 1302
Tolerance — OD ±0.05 mm (±0.002") for precision grades EN 10217-1
Tolerance — Wall Thickness ±10% of nominal thickness ASTM A554
Tolerance — Straightness (uncoiled) ≤ 1.5 mm/m EN 10217-1
Material Grades Available 304, 304L, 316, 316L, 321, 310S, 430, 904L, Duplex 2205 ASTM, EN, JIS, GB
End Condition Open ends, beveled ends, or custom formed Customer Specification
Packaging Industrial coil spools with protective wrapping, wooden or steel crates ISO 4180

4. Manufacturing Process

The production of stainless steel coil tubes involves a multi-stage manufacturing sequence combining hot rolling, cold drawing, and continuous coiling operations to achieve precise dimensional tolerances and superior surface quality.

4.1 Process Flow

  1. Raw Material Procurement: High-purity stainless steel billets or slabs are sourced from certified mills, undergoing incoming inspection for chemical composition (spectrometric analysis) and mechanical properties.
  2. Hot Rolling / Hot Extrusion: Billets are heated to 1100–1250°C (2012–2282°F) and hot-rolled or extruded through calibrated dies to produce initial tube blanks with approximate target dimensions.
  3. Pickling & Descaling: The hot-rolled tube undergoes acid pickling (typically using a mixture of hydrofluoric acid and nitric acid) to remove oxide scale, restoring the base metal's corrosion resistance.
  4. Acid Cleaning & Annealing: The pickled tube is annealed in a controlled atmosphere (vacuum or inert gas) at 1050–1150°C (1922–2092°F) to relieve internal stresses, refine grain structure, and achieve desired mechanical properties.
  5. Cold Drawing / Cold Pilgering: The annealed tube is cold-drawn through precision tungsten carbide dies to achieve final dimensions, surface finish, and tight tolerances. This stage is critical for achieving the dimensional accuracy required by downstream applications.
  6. Intermediate Annealing: Multiple drawing passes may require intermediate annealing cycles to restore ductility and prevent work-hardening failures.
  7. Surface Finishing: Depending on the application, tubes receive additional surface treatments including electropolishing, mechanical polishing, brushing, or passivation (using citric acid or nitric acid solutions to form a protective chromium oxide layer).
  8. Coiling: The finished tube is wound onto precision-mandrel coil spools under controlled tension to prevent deformation, kinking, or surface damage. The coiling process is executed at a constant linear speed with synchronized tension control.
  9. Quality Inspection: Each coil undergoes rigorous inspection including dimensional verification (OD, wall thickness, straightness), surface quality assessment, hydrostatic pressure testing, and non-destructive testing (eddy current or ultrasonic).
  10. Packaging & Dispatch: Inspected coils are wrapped with protective film or paper, secured on wooden pallets or steel crates, and prepared for shipment.

4.2 Quality Control Measures

5. Applications

Stainless steel coil tubes find extensive application across diverse industrial sectors due to their combination of corrosion resistance, mechanical strength, hygienic surface properties, and processing versatility.

5.1 Key Application Areas

6. Quality Certifications & Standards Compliance

Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring that all stainless steel coil tube products meet or exceed internationally recognized standards.

6.1 Management System Certifications

6.2 Product Standard Compliance

6.3 Material Traceability

Each coil of stainless steel tube is accompanied by a Mill Test Certificate (MTC) or En 10204 3.1 Certificate, providing full traceability of chemical composition, mechanical properties, heat treatment records, and dimensional verification data. This documentation ensures compliance with customer quality requirements and regulatory mandates across all target markets.

7. Unique Selling Points