CNC Machining worked example

Chip Load with feed rate of 240 in / min: a worked example

Push feed rate up to 240 in / min and the picture changes. This example computes every intermediate figure at that operating point. checking actual chip thickness from a programmed feed rate before changing RPM, feed override, flute count, or cutter selection

The inputs for this scenario

  • Feed rate: 240 in / min (raised for this scenario; the documented default is 96)
  • Spindle speed: 8,000 RPM (unchanged)
  • Flute divisor: 0.33 1 / flutes (unchanged)

Working through the calculation

  • Applying the documented formula (Chip load = programmed feed rate ÷ spindle speed × flute divisor) to the inputs above produces each figure below.
  • At this operating point the engine returns 0.01 in / tooth for feed per revolution before flute divisor, the number this scenario is built around.
  • At this operating point the engine returns 0.03 value for raw ratio.
  • At this operating point the engine returns 0.33 x for conversion factor.
  • At this operating point the engine returns 8,000 value for spindle speed.

How this compares with the baseline

  • Against the tool's baseline example, where feed rate sits at 96 in / min and the headline result is 0 in / tooth, this scenario comes in 150% above the baseline at 0.01 in / tooth.
  • It computes feed per tooth by dividing the programmed feed rate by spindle speed and applying the flute divisor. 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

  • feed per revolution before flute divisor: 0.01 in / tooth (headline result)
  • Raw ratio: 0.03 value
  • Conversion factor: 0.33 x
  • spindle speed: 8,000 value

Run it with your numbers

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

Last reviewed 2026-05-12.