CNC Machining worked example

Tapping Cycle Time at 22% reversal, sync, and retract allowance: a worked example

Suppose reversal, sync, and retract allowance falls to 22%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate tapping cycle time from thread depth, tapping feed, and allowance for reversal, synchronization, entry, and retract moves.

The inputs for this scenario

  • total thread depth: 24 in (held at the documented default)
  • tapping feed rate: 10 in / min (held at the documented default)
  • reversal, sync, and retract allowance: 22 % (the input this scenario stresses; the baseline uses 30)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base tapping cycle time = total thread depth รท tapping feed rate.
  • estimated tapping cycle time works out to 2.93 min at these inputs, and this is the headline figure for the scenario.
  • base tapping cycle time works out to 2.4 min at these inputs.
  • reversal, sync, and retract allowance works out to 22 % at these inputs.
  • tapping feed rate works out to 10 pieces / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where reversal, sync, and retract allowance sits at 30% and the headline result is 3.12 min, this scenario comes in 6.15% below the baseline at 2.93 min.
  • It divides total thread depth by the tapping feed rate for base time, then multiplies by an allowance factor for spindle reversal, synchronization, and retract. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • estimated tapping cycle time: 2.93 min (headline result)
  • base tapping cycle time: 2.4 min
  • reversal, sync, and retract allowance: 22 %
  • tapping feed rate: 10 pieces / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Tapping Cycle Time calculator, set reversal, sync, and retract allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.