Clearance and Interference Calculator
Calculates worst-case clearance between a hole and shaft. The page includes a worked condition, equation trace, operating assumptions, and checking guidance. The example is meant to be traced from the labeled entries to minimum clearance, including the units that survive the equation.
Enter the study values
Minimum clearance
Using minimum clearance only under matched conditions
A negative result represents interference under the stated limit combination; geometric errors and temperature may also matter.
Stability, distribution shape, measurement error, subgrouping, drift, and sampling design can shift a quality result. The page keeps that boundary visible beside minimum clearance.
If the next quality metric changes, continue with rss tolerance stack and unilateral to bilateral tolerance.
A separate cross-check is available in the manufacturing quality rate when minimum clearance influences work outside this quality control step.
Interpreting the scale of minimum clearance
The equation uses minimum hole diameter, maximum shaft diameter to report minimum clearance in mm. A negative result represents interference under the stated limit combination; geometric errors and temperature may also matter.
The sample minimum clearance is 0.04 millimeter.
Minimum clearance: interpreting an increase or decrease
Treat the worked value as a baseline, then alter one of minimum hole diameter, maximum shaft diameter while leaving the other entries fixed. Predict the direction and approximate size of the change before reading the new minimum clearance. This separates a real relationship in the formula from a typing error or an unnoticed unit conversion.
Test clearance and interference at the observed edges of the setup rather than at arbitrary extreme numbers. This reveals whether ordinary variation materially changes minimum clearance.
When checking minimum clearance, compare like with like: retain the same part definition and calculation boundary unless the purpose of the test is to change them explicitly.
Minimum clearance: conclusions supported by the calculation
Interpret minimum clearance only after measurement-system adequacy, subgrouping, process stability, and the distinction between control and specification limits have been established.
Preserve the entered minimum hole diameter and maximum shaft diameter in the control plan. If either changes, rerun the relationship and identify the revised characteristic, measurement system, subgroup, and sampling period rather than editing a rounded result.
Minimum clearance: testing the direction of change
Estimate the order of magnitude before calculating. Then change one input while holding the others fixed and predict whether minimum clearance should rise or fall.
Rearrange Clearance = Dhole min - Dshaft max to recover one entered value. Agreement with the source record checks the algebra in a different direction.
Minimum clearance: stability across realistic inputs
Quality measurements, limits, subgroup definitions, defect rules, and sampling periods should share one study boundary. That distinction matters before minimum clearance is carried into later work.
Do not overwrite the original observation with a corrected minimum clearance. Keep both versions of the clearance and interference record so the reason for the revision remains visible.
Minimum Hole Diameter as a driver of minimum clearance
Write the equation for minimum clearance symbolically and identify the role of minimum hole diameter, maximum shaft diameter. A value that belongs to another run or geometry should not be substituted merely because its unit fits.
Check constants and conversion factors against the unit system used by minimum hole diameter, maximum shaft diameter. This is especially important before reporting minimum clearance in mm.
Minimum clearance: practical meaning in context
Store minimum clearance 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.
Store a guard-digit version of minimum clearance for follow-on work and a rounded version for communication. Label them so one is not mistaken for the other.
Using the minimum clearance answer
When should minimum clearance be recalculated?
Recalculate after a change to minimum hole diameter, maximum shaft diameter, the operating boundary, or the governing procedure. Start from the revised inputs rather than scaling the previous answer.
What should be saved beside minimum clearance?
Retain the entered values, their units, the date or revision, and the relationship Clearance = Dhole min - Dshaft max. That record is more useful than an isolated rounded answer.
What unit should the minimum clearance answer use?
The answer is reported in mm. Carry the input units through the equation rather than attaching that label after the arithmetic.
How much precision is useful for minimum clearance?
Keep guard digits while checking or reusing the result, then round to the resolution supported by minimum hole diameter and the next decision.
How should two minimum clearance cases be compared?
Change one uncertain input at a time, label each condition, and compare the resulting minimum clearance values before building a combined best- or worst-case scenario.
Is minimum clearance a measured value?
Minimum clearance is calculated from the labeled entries, including minimum hole diameter and maximum shaft diameter. Actual performance may differ because the equation does not represent every loss, tolerance, or source of variation.