GD&T Geometric Symbols & Notation 3

Question 1

The GD&T symbol for 'Angularity' controls which characteristic?

Accepted Answer

The orientation of a surface at a specified angle to a datum

Answer

Angularity is an orientation control that constrains a surface or axis to a specified angle (other than 0° or 90°) relative to a datum.

Question 2

What is the purpose of a 'projected tolerance zone' modifier (circled P) in GD&T?

Accepted Answer

Extends the tolerance zone beyond the part surface to control mating part fit

Answer

A projected tolerance zone extends the positional tolerance zone above the hole to control the orientation of a fastener as it protrudes into a mating part.

Question 3

Which feature control frame compartment always contains the geometric characteristic symbol?

Accepted Answer

The first (leftmost) compartment

Answer

Per ASME Y14.5, the first compartment of a feature control frame always contains the geometric characteristic symbol.

Question 4

What does 'BASIC' written below a dimension value indicate in a GD&T drawing?

Accepted Answer

The dimension is theoretically exact and has no tolerance of its own

Answer

A basic dimension (shown in a box or labeled BASIC) is a theoretically exact value; its allowable variation is defined by the feature control frame tolerance.

Question 5

The GD&T symbol for 'Circular Runout' differs from 'Total Runout' in that:

Accepted Answer

Circular runout is checked at individual cross-sections, while total runout accumulates across the entire surface

Answer

Circular runout measures the variation at each individual circular cross-section independently, while total runout measures the combined variation over the entire surface.

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

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

GD&T Geometric Symbols & Notation 3