Runout and Concentricity Flashcards
7 cards from real GD&T practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Runout and Concentricity flashcards as text
What is the key difference between circular runout and total runout?
Answer: Circular runout applies to a single cross-section while total runout applies along the entire surface
Circular runout measures deviation at individual cross-sections, whereas total runout accumulates error across the entire length of the surface.
When a runout tolerance is applied to a conical surface, what does the tolerance zone represent?
Answer: Two lines along the cone surface separated by the tolerance value
For conical surfaces, the runout tolerance zone consists of two lines on the cone surface separated by the tolerance value, measured perpendicular to the surface.
A shaft has a total runout tolerance of 0.05 mm. During inspection, the FIM (Full Indicator Movement) reading is 0.04 mm. The part is:
Answer: Accepted because the FIM is within the 0.05 mm tolerance
The part passes because the measured FIM of 0.04 mm is less than the specified total runout tolerance of 0.05 mm.
Concentricity is most accurately described as a control of:
Answer: The median points of diametrically opposed surface elements relative to a datum axis
Concentricity controls the location of the derived median points of all diametrically opposed surface elements, not the surface itself.
Which of the following characteristics makes concentricity difficult to verify?
Answer: It requires deriving median points from opposing surface elements rather than direct surface measurement
Finding median points of diametrically opposed elements requires complex calculations, making concentricity verification more difficult than runout.
A designer wants to control wobble of a rotating disk face. Which GD&T control is most appropriate?
Answer: Circular runout applied to the face
Circular runout applied to a face (axial runout) directly controls wobble of a rotating surface relative to a datum axis.
In GD&T, what does MMC (Maximum Material Condition) bonus tolerance apply to for runout callouts?
Answer: MMC bonus tolerance is not applicable to runout tolerances
Runout is a surface control and cannot use MMC or LMC modifiers because it applies directly to surfaces, not to axes or center planes.