CNC Machining worked example

Tapping Cycle Time at 35% reversal, sync, and retract allowance: a worked example

Push reversal, sync, and retract allowance up to 35% and the picture changes. This example computes every intermediate figure at that operating point. estimating tapping cycle time for quoting, routing, capacity planning, or comparing alternate CNC programs

The inputs for this scenario

  • total thread depth: 24 in (unchanged)
  • tapping feed rate: 10 in / min (unchanged)
  • reversal, sync, and retract allowance: 35 % (raised for this scenario; the documented default is 30)

Working through the calculation

  • Applying the documented formula (Base tapping cycle time = total thread depth รท tapping feed rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 3.24 min for estimated tapping cycle time, the number this scenario is built around.
  • At this operating point the engine returns 2.4 min for base tapping cycle time.
  • At this operating point the engine returns 35 % for reversal, sync, and retract allowance.
  • At this operating point the engine returns 10 pieces / min for tapping feed rate.

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 3.85% above the baseline at 3.24 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. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • estimated tapping cycle time: 3.24 min (headline result)
  • base tapping cycle time: 2.4 min
  • reversal, sync, and retract allowance: 35 %
  • tapping feed rate: 10 pieces / min

Run it with your numbers

  • Every input above is editable in the live Tapping Cycle Time calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.