GD&T Geometric Symbols & Notation 2

Question 1

Which GD&T symbol is used to control the orientation of a surface or axis to a datum without controlling its location?

Accepted Answer

Parallelism

Answer

Parallelism controls orientation (angle = 0°) relative to a datum but does not control the feature's location.

Question 2

The 'all around' symbol in GD&T is represented by:

Accepted Answer

A circle on the bend of the leader line

Answer

A circle placed at the bend of the leader line indicates the profile tolerance applies all around the cross-section.

Question 3

What does the symbol 'Ø' placed before a tolerance value in a feature control frame indicate?

Accepted Answer

The tolerance zone is cylindrical

Answer

The diameter symbol (Ø) before a tolerance value specifies a cylindrical (3D) tolerance zone rather than two parallel planes.

Question 4

A free state variation symbol in GD&T is depicted as:

Accepted Answer

A circled F

Answer

The circled F modifier indicates that the tolerance applies to the part in its free (unrestrained) state.

Question 5

Which symbol indicates that a feature of size must be at its maximum material condition boundary?

Accepted Answer

Circled M

Answer

The circled M (MMC modifier) in a feature control frame means the stated tolerance applies when the feature is at its maximum material condition.

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