Machining

Feed per Tooth Calculator

Finds chip load per tooth from programmed feed, RPM, and tooth count. The starting values provide a baseline that can be compared with a realistic high or low machining condition.

Machining inputs

Set the tool and machine values

in/min
rpm
teeth
Calculated result

Feed per tooth

Result
—
fz = F / (RPM z)

    Feed Per Tooth within the stated process boundary

    Estimate the order of magnitude before calculating. Then change one input while holding the others fixed and predict whether feed per tooth should rise or fall.

    Rearrange fz = F / (RPM z) to recover one entered value. Agreement with the source record checks the algebra in a different direction.

    Where feed per tooth fits in the operating decision

    The equation uses feed rate, spindle speed, number of teeth to report feed per tooth in in/tooth. Runout can make individual teeth carry unequal chips even when the calculated average is acceptable.

    A 32 in/min feed over 2,000 rpm and four teeth equals 0.004 inch per tooth.

    Feed per tooth: practical meaning in context

    Tool diameter, engagement, feed, speed, and material data should describe the same operation rather than a mixture of catalog maxima and actual settings. This page preserves feed rate and number of teeth with the answer for that reason.

    The source trail matters when feed per tooth feeds another operation. Save the measured values, selected standard, and any inclusion rule that defined the feed per tooth boundary.

    Changing feed rate while number of teeth stays fixed

    Treat the worked value as a baseline, then alter one of feed rate, spindle speed, number of teeth while leaving the other entries fixed. Predict the direction and approximate size of the change before reading the new feed per tooth. This separates a real relationship in the formula from a typing error or an unnoticed unit conversion.

    A small scenario table can clarify feed per tooth: retain the baseline, change one field to a credible low value, then to a credible high value, and compare the three results.

    Do not assemble a favorable result from measurements taken on incompatible runs. A feed per tooth scenario should represent one feasible production or fabrication state.

    Feed per tooth: conclusions supported by the calculation

    Begin the feed per tooth check by identifying the requested feed per tooth, the governing equation, and the source of feed rate, spindle speed, number of teeth. Only then insert the sample or measured values.

    fz = F / (RPM z)

    The numerical answer and its dimension are one result. Preserve both while checking feed per tooth, and reject a finite value whose units do not reduce to in/tooth.

    Feed per tooth: assumptions to review before release

    Runout can make individual teeth carry unequal chips even when the calculated average is acceptable.

    Machine dynamics, tool runout, wear, chatter, coolant delivery, workholding, and material variation can make the safe shop setting differ from a theoretical value. Here, the recorded feed rate determines how that guidance is applied.

    Feed per tooth: focus on number of teeth: practical meaning in context

    Store feed per tooth with its input values, units, date, product or operation, and the equation version. Do not let extra displayed digits imply measurement accuracy the source data did not have.

    Match the final feed per tooth precision to the process capability, measurement method, or costing convention rather than to the calculator display.

    Questions about feed per tooth

    Can feed rate and number of teeth come from different runs?

    Only when they describe a combination that can occur together. Preserve the same machine, tool, material, and cutting condition throughout the calculation. Here, the recorded feed rate determines how that guidance is applied.

    Which entry has the strongest effect on feed per tooth?

    Inspect the exponents, products, and divisors in fz = F / (RPM z). Then change feed rate by a controlled amount while leaving the other fields fixed.

    How can the feed per tooth arithmetic be checked independently?

    Use fz = F / (RPM z), solve backward for one known entry, and compare it with the original record. A unit check provides a second test.

    Does the calculated feed per tooth replace the governing specification?

    No. The calculated feed per tooth evaluates one stated relationship; drawings, procedures, control plans, equipment limits, and acceptance rules still govern the work.

    When should feed per tooth be recalculated?

    Recalculate after a change to feed rate, number of teeth, the operating boundary, or the governing procedure. Start from the revised inputs rather than scaling the previous answer.