Tool Runout vs Chip Load Calculator

Inputs

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The chip load in the program — after any chip-thinning compensation. 0.0508 mm = 0.002 in.
in
Total indicator reading at the cutting edges, in the holder, at working stickout — not the spindle taper alone.
in
The bound is exact for 2 flutes and conservative for more.
flutes

Results

Default result
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Runout ÷ chip load
25%
Caution

Runout is 25% of the chip load — tooth loads swing ±25%. Edge wear concentrates on the high flutes and finish shows it; tighten the runout or raise the feed per tooth.

The commonly quoted shop guideline keeps this under ~10%.

Also computed

Heaviest tooth chip(f_max)0.0025in

Lightest tooth chip(f_min)0.0015in

Allowable TIR (10% rule)0.0002in

The runout budget your feed per tooth supports.

Method notes 4 notes
  • Bound model: f_z ± TIR is exact for 2 diametrically opposed flutes and conservative for more (pure-eccentricity adjacent-tooth differences stay inside ±TIR). Tilt-type runout at long stickout behaves worse than this screen shows.
  • Measure TIR at the cutting edges in the actual holder at working stickout — taper-only readings flatter the setup.
  • Light chips amplify the problem: after HSM chip-thinning compensation the PROGRAMMED feed is the right denominator, but at very small actual chips even good holders eat a large share (see the radial chip thinning calculator).
  • Runout shortens tool life faster than the average load suggests — the high tooth wears at its own rate, then hands its work to the next.

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