GD&T Datum Systems & Reference Frames 4

Question 1

What is the primary purpose of applying the MMC modifier (M) to a datum feature reference?

Accepted Answer

To allow datum shift when the datum feature departs from MMC

Answer

When MMC is applied to a datum feature reference, bonus datum shift is permitted as the datum feature departs from its maximum material condition.

Question 2

Datum shift is allowed when which modifier is applied to a datum feature of size?

Accepted Answer

Both MMC and LMC, but not RFS

Answer

Datum shift is available when either MMC or LMC is applied to a datum feature of size reference; RFS requires the datum to be derived without shift.

Question 3

Which of the following is NOT a type of datum target?

Accepted Answer

Datum target volume

Answer

Datum targets are defined as points, lines, or areas; there is no 'datum target volume' in GD&T per ASME Y14.5.

Question 4

In a datum reference frame, what does the term 'degrees of freedom' refer to?

Accepted Answer

The independent modes of translation and rotation of a part in space

Answer

Degrees of freedom are the six independent ways a rigid body can move in 3D space: three translations (X, Y, Z) and three rotations (u, v, w).

Question 5

A movable datum target is identified on a drawing by:

Accepted Answer

Two parallel horizontal lines below the datum target symbol

Answer

A movable datum target is indicated by two parallel horizontal lines (a slide symbol) beneath the standard datum target symbol to indicate it can be repositioned.

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

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

GD&T Datum Systems & Reference Frames 4