Cylindricity & Runout (TIR) Calculator

Inputs

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Highest dial-indicator reading as the part is rotated one full turn about its datum axis.
mm
Lowest dial-indicator reading over the same full rotation (can be negative).
mm
Runout tolerance from the feature control frame, to check pass/fail.
mm
Largest diameter measured over the full length of the cylindrical surface.
mm
Smallest diameter measured over the full length of the cylindrical surface.
mm

Results

Default result
Edit inputs
Runout (TIR)
0.04mm
Pass

Within tolerance.

Max reading − min reading (full indicator movement).

Also computed

Cylindricity zone0.02mm

(max Ø − min Ø) ÷ 2

Method notes 2 notes
  • Runout (TIR) is the total indicator reading: the full sweep of the indicator, max − min, as the part turns about its datum axis.
  • Cylindricity is a form control — the radial band (max radius − min radius) containing the whole surface, independent of any datum: (max Ø − min Ø) ÷ 2.

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