Stainless Steel Coil Tube — ASTM A269 Seamless & Welded Austenitic Tubes

Product Overview

The ASTM A269 standard defines the requirements for seamless and welded austenitic stainless steel tubes, covering a broad range of grades including but not limited to Type 304, 316, 321, 347, and 904L. As the most widely cited general-purpose standard in international trade for austenitic stainless steel tubing, ASTM A269 serves as the definitive benchmark for material quality, dimensional tolerances, and mechanical performance across global supply chains.

Wenzhou Jixing Metal Materials Co., Ltd. supplies coil tube (盘管) products manufactured in strict compliance with ASTM A269, offering both seamless and welded configurations in continuous coil form. The coil format provides significant advantages in downstream processing — including bending, forming, and cut-to-length operations — while minimizing material waste and optimizing inventory management for end users.

Material & Properties

Austenitic Stainless Steel Grades Covered

Mechanical Properties (Typical)

Key Material Characteristics

Specifications

Parameter Specification Reference
Standard ASTM A269 / A269M Current Edition
Product Form Coil Tube (Continuous Coil) —
Manufacturing Method Seamless and Welded (ERW / Argon Arc Welded) ASTM A269
Outer Diameter (OD) 6.35 mm – 168.3 mm (¼ in. – 6½ in.) ASTM A269 Table 1
Wall Thickness 0.5 mm – 9.5 mm (0.020 in. – 0.375 in.) ASTM A269
OD Tolerance ± 0.02 in. (± 0.5 mm) or better ASTM A269
Wall Thickness Tolerance ± 10% of nominal ASTM A269
Surface Finish Commercial Annealed (Bright Annealed Available on Request) —
Coil Weight Up to 2,500 kg (5,500 lb) per coil —
End Condition Plain, Beveled, or Threaded (on Request) —
Heat Treatment Annealed and Pickled (Solution Annealed) ASTM A269
Deliverable Condition Annealed (A), Solution Heat Treated (SHT) ASTM A269

Manufacturing Process

Seamless Coil Tube

  1. Hot Rolling: Billet material is hot-rolled into a hollow shell (skillet) at temperatures above 1,200 °C.
  2. Piercing & Elongation: The shell is pierced using a Mannesmann-type or plug piercing mill, followed by multi-stand elongation rolling to reduce wall thickness and achieve target OD.
  3. Intermediate Annealing: Tubes are annealed to relieve residual stresses and restore ductility for further cold working.
  4. Cold Drawing / Sizing: Tubes pass through a series of draw plates or roller sizing stands to achieve precise dimensional tolerances and smooth surface finish.
  5. Final Annealing & Pickling: Solution annealing at 1,050–1,150 °C followed by rapid quenching, then acid pickling to remove scale and restore the passive chromium oxide layer.
  6. Coiling: Finished tubes are wound onto precision coils with controlled tension to prevent deformation.

Welded Coil Tube

  1. Strip Forming: Cold-rolled stainless steel strip is fed through a series of roll forming stations to produce a tubular shape with a longitudinal seam.
  2. Welding: The seam is welded using either Electric Resistance Welding (ERW) or Automatic Argon Arc Welding (TIG), depending on grade and wall thickness requirements.
  3. Weld Inspection: Non-destructive testing (eddy current or ultrasonic) ensures weld integrity along the entire length.
  4. Heat Treatment: Solution annealing in a continuous annealing furnace under protective atmosphere to homogenize microstructure and achieve the required mechanical properties.
  5. Pickling & Passivation: Acid cleaning followed by passivation treatment to ensure full corrosion resistance.
  6. Coiling & Packaging: Tubes are coiled, protected with VCI (Volatile Corrosion Inhibitor) film or wooden spools, and shrink-wrapped for shipment.

Applications

Quality Certifications & Compliance

Unique Selling Points

Industry-Leading Standard Compliance: ASTM A269 is recognized as the most universally accepted standard for austenitic stainless steel tubing in international trade, ensuring seamless integration into global procurement systems without the need for standard conversion or re-certification.