GD&T Runout and Concentricity 3

Question 1

Which datum reference is required for a runout tolerance callout?

Accepted Answer

A datum axis

Answer

Runout tolerances always require a datum axis because the surface elements are measured relative to rotation about that axis.

Question 2

A cylindrical surface has a circular runout tolerance of 0.03 mm and is also controlled by a size tolerance of ±0.1 mm. Which statement is correct?

Accepted Answer

Both tolerances must independently be satisfied

Answer

Size and runout are independent controls; a feature must conform to both its size tolerance and its runout tolerance separately.

Question 3

Total runout when applied to a cylindrical surface simultaneously controls which combination of errors?

Accepted Answer

Cylindricity, coaxiality, and taper

Answer

Total runout on a cylinder controls all surface variations including out-of-roundness, wobble, taper, waviness, and coaxiality errors.

Question 4

A part drawing shows a runout callout with two datum references (e.g., A-B). What does this typically indicate?

Accepted Answer

The datum axis is established by two datum features used together

Answer

Two datum references for runout typically establish a common datum axis from two separate datum features used simultaneously.

Question 5

Why is symmetry sometimes used as an alternative to concentricity for symmetric features?

Accepted Answer

Symmetry is easier to apply to non-round features than concentricity

Answer

Symmetry controls the median points of features relative to a datum plane, making it applicable to non-cylindrical symmetric features where concentricity is not appropriate.

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

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

GD&T Runout and Concentricity 3