How do you calculate tube expansion time?

Divide the number of tubes by the expansion rate to get base hours, then multiply by one plus the allowance. For 120 tubes at 12 tubes/hr with a 10% allowance, base time is 10 hours and adjusted time is 11 hours.

What is a typical tube expansion rate?

It varies widely by method and tube size, roller expanders, hydraulic expansion and torque-controlled tools all differ. The default 12 tubes/hr is illustrative; measure your own station and enter the real rate for a meaningful estimate.

Why add an expansion allowance?

A raw rate ignores tool changes, mandrel wear, mis-expands and re-rolls. The 10% allowance turns a clean 10-hour base into a realistic 11 hours so the schedule does not slip.

Does this include brazing or leak testing?

No. This figure covers only the mechanical expansion operation. Brazing, leak test and final assembly are separate operations you should estimate and schedule independently.

How do I speed up tube expansion?

Reduce the allowance by cutting tool changes and rework, or raise the expansion rate with multi-tube tooling or hydraulic expansion. Both directly shrink the 11-hour result for this batch.

Tube expansion time vs total assembly time?

Expansion time is one operation; total assembly also includes loading, brazing, leak test and pack-out. Use this number as the expander-station input to a fuller line balance, not as the whole coil's labor.

Heat Exchanger, Coil & Radiator Manufacturing calculator

Tube Expansion Time Calculator

Tube expansion time estimates the labor hours to mechanically expand a batch of tubes into header or fin collars, the step that creates the tube-to-fin or tube-to-tubesheet joint that carries the coil's pressure and heat transfer. Process planners and line leads on coil and radiator lines use it to schedule the expander station, staff a shift, and quote the labor content of the expansion operation. Because expansion is often a bottleneck between assembly and brazing, a tight hour estimate keeps the whole line flowing. The allowance factor lets you add realistic time for tool changes, mis-expands and re-rolls that a raw rate ignores.

What this calculator does

Estimate adjusted tube expansion time for finned coils and tube bundles from tubes to expand, expansion rate, and allowance.
Use it when mechanical expansion, bullet expansion, mandrel expansion, or roll expansion needs to be scheduled before brazing, leak testing, or final assembly.
It computes adjusted expansion hours by dividing tube count by the expansion rate and inflating the result with an allowance for setup, tool changes and rework.

Formula used

Base tube expansion hours = tubes to expand ÷ expansion rate
Adjusted tube expansion hours = base tube expansion hours × allowance factor

Inputs explained

Tubes to expand:
Expansion rate:
Expansion allowance:

How to use the result

Use it when scheduling the expander station, staffing a coil build, or quoting the labor hours of the mechanical or hydraulic expansion operation.
It assumes one steady expansion rate; mixed tube diameters, wall thicknesses or alloys that change cycle time mid-batch are not captured by a single rate.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).

Common questions

How do you calculate tube expansion time? Divide the number of tubes by the expansion rate to get base hours, then multiply by one plus the allowance. For 120 tubes at 12 tubes/hr with a 10% allowance, base time is 10 hours and adjusted time is 11 hours.
What is a typical tube expansion rate? It varies widely by method and tube size, roller expanders, hydraulic expansion and torque-controlled tools all differ. The default 12 tubes/hr is illustrative; measure your own station and enter the real rate for a meaningful estimate.
Why add an expansion allowance? A raw rate ignores tool changes, mandrel wear, mis-expands and re-rolls. The 10% allowance turns a clean 10-hour base into a realistic 11 hours so the schedule does not slip.
Does this include brazing or leak testing? No. This figure covers only the mechanical expansion operation. Brazing, leak test and final assembly are separate operations you should estimate and schedule independently.
How do I speed up tube expansion? Reduce the allowance by cutting tool changes and rework, or raise the expansion rate with multi-tube tooling or hydraulic expansion. Both directly shrink the 11-hour result for this batch.

Last reviewed 2026-05-12.