GD&T Runout and Concentricity 4

Question 1

What instrument is most commonly used to measure runout in a production environment?

Accepted Answer

Dial test indicator (DTI) with the part rotating on centers or in a chuck

Answer

A dial test indicator placed against the surface while the part rotates on centers or in a V-block is the standard production method for measuring runout.

Question 2

If a shaft is bent (curved axis), which runout measurement will show the largest FIM reading?

Accepted Answer

Total runout along the full length

Answer

Total runout captures all cumulative surface deviations including the effect of a bent axis along the entire length, giving the largest FIM reading.

Question 3

Concentricity is removed from ASME Y14.5-2018. What control replaces it for most design intents?

Accepted Answer

Coaxiality using position

Answer

ASME Y14.5-2018 removed concentricity and recommends using position applied to the axis (coaxiality) as a more verifiable replacement.

Question 4

A print specifies circular runout of 0.05 mm on a journal bearing surface. The measured FIM at one cross-section is 0.06 mm. What action should be taken?

Accepted Answer

Reject the part as it exceeds the specified tolerance

Answer

Circular runout must be within tolerance at every cross-section; a single cross-section exceeding 0.05 mm causes rejection.

Question 5

Which of the following best describes the tolerance zone for total runout on a cylindrical surface?

Accepted Answer

Two coaxial cylinders with a radial distance equal to the tolerance value

Answer

The total runout tolerance zone for a cylinder is defined by two coaxial cylinders, one inside the other, separated by the stated tolerance value.

(GD&T) Geometric Dimensioning and Tolerancing Certification Practice Test

(GD&T) Geometric Dimensioning and Tolerancing Certification Practice Test

GD&T Runout and Concentricity 4