GD&T Runout and Concentricity 5

Question 1

A turbine rotor requires tightly controlled vibration during operation. Which GD&T control best addresses dynamic balance concerns related to surface geometry?

Accepted Answer

Total runout on the rotating cylindrical surfaces

Answer

Total runout on cylindrical surfaces controls all geometric deviations that contribute to mass imbalance and vibration in rotating equipment.

Question 2

Which statement correctly compares the verification complexity of concentricity versus coaxial position?

Accepted Answer

Coaxial position is easier because it can be verified using a functional gauge or CMM axis measurement

Answer

Coaxial position (axis-to-axis) can be verified with a functional gauge or CMM axis fit, while concentricity requires finding median points which is mathematically complex.

Question 3

A circular runout symbol (single arrow circle) is placed on a drawing. What is the standard symbol used?

Accepted Answer

A circle with a single diagonal arrow

Answer

The circular runout symbol in GD&T is a circle with a single diagonal arrow, distinguishing it from total runout which uses a double arrow.

Question 4

For a part with both runout and position callouts on the same surface, which takes precedence?

Accepted Answer

Both must be independently satisfied; neither overrides the other

Answer

When both runout and position are called out on the same feature, each must be independently verified and satisfied.

Question 5

A design engineer specifies runout instead of cylindricity on a bearing journal. What is a key advantage of this decision?

Accepted Answer

Runout relates the surface to a datum axis relevant to function, while cylindricity does not reference a datum

Answer

Runout ties surface quality to the functional datum axis (how the part actually rotates), while cylindricity only controls the surface form without a datum reference.

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

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

GD&T Runout and Concentricity 5