ASME ASME Geometric Dimensioning and Tolerancing 2

Question 1

What does 'true position' mean in ASME Y14.5 GD&T?

Accepted Answer

The theoretically exact location of a feature defined by basic dimensions

Answer

True position is the theoretically exact location of a feature, defined by basic (boxed) dimensions from the datum reference frame.

Question 2

Which symbol is used in GD&T to control the circular cross-section of a cylinder at any cross-section?

Accepted Answer

Circularity (roundness)

Answer

Circularity (roundness) controls each circular cross-section of a cylinder independently, requiring all points to lie within an annular zone.

Question 3

Under ASME Y14.5, what is a 'basic dimension'?

Accepted Answer

A theoretically exact value from which toleranced dimensions are established

Answer

A basic dimension is a theoretically exact value, enclosed in a box, used to establish the true position or profile of a feature; tolerances come from the feature control frame.

Question 4

What geometric characteristic is used to control both size and form of a complete cylindrical feature?

Accepted Answer

Cylindricity

Answer

Cylindricity controls the form of an entire cylindrical surface, requiring all points to lie between two coaxial cylinders, combining roundness, straightness, and taper.

Question 5

In GD&T, 'total runout' controls which combination of errors?

Accepted Answer

All surface variations relative to a datum axis including wobble, taper, and form

Answer

Total runout measures all surface deviations — including circular runout, taper, straightness, and form — across the entire surface relative to the datum axis.

ASME - American Society of Mechanical Engineers Practice Test

ASME - American Society of Mechanical Engineers Practice Test

ASME ASME Geometric Dimensioning and Tolerancing 2