Integrated manufacturing + export coordination

Technical guide / updated 2026-08-25

Tube Diameter and Wall Thickness for Custom Coils

Tube outside diameter and wall thickness should be stated separately and shown with units. They influence the available bend geometry, connections and project review, but they cannot be selected from one value alone.

State OD and wall clearly

Use a format such as tube OD × wall thickness and include the material grade. Do not substitute nominal connection size for actual tube dimensions.

  • Tube outside diameter
  • Wall thickness
  • Material grade
  • Dimensional standard if controlled

Connect tube size to the geometry

Provide the required coil diameter, straight legs, pitch, number of turns and bend radii. The fabricator can then review whether the requested route is compatible with the defined tube.

  • Coil or bend diameter
  • Pitch and turn count
  • Straight-leg length
  • Overall envelope and tolerances

Add the operating basis

Pressure, temperature, medium and duty are part of the engineering review. Final wall and material selection should follow the approved project design and applicable requirements.

  • Internal and external media
  • Operating and design pressure
  • Temperature range
  • Required inspection or test

Use catalog examples correctly

The Uniinox custom coil catalog contains 304 stainless reference configurations at Ø9.52, Ø12 and Ø22 mm. These examples show documented geometries, not universal design recommendations.

  • Ø9.52 × 0.7 reference
  • Ø12 × 0.8 reference
  • Ø22 × 1.0 references
  • Approved drawing controls production

Frequently asked questions

Project questions

Is tube OD the same as connection size?

Not necessarily. State both the actual tube dimensions and the required connection details.

Can I choose wall thickness from the website alone?

No. The final selection depends on material, pressure, temperature, medium, forming geometry and the approved design basis.