GD&T Composite Feature Control 3

Question 1

A bolt pattern uses composite position with PLTZF ⌀1.0|A|B|C and FRTZF ⌀0.4|A. What does datum A control in the FRTZF?

Accepted Answer

Perpendicularity (orientation) of each hole to datum A

Answer

In the FRTZF, datum A (a flat surface) controls only the orientation (perpendicularity) of each hole relative to datum A, not the hole pattern's location.

Question 2

What is the key geometric difference between the PLTZF and FRTZF tolerance zones?

Accepted Answer

PLTZF zones are fixed in space relative to datums; FRTZF zones can translate as a group

Answer

The PLTZF zones are located at true position relative to the datum reference frame, while the FRTZF zones can translate as a group but must maintain their internal pattern geometry.

Question 3

The simultaneous requirement applies to composite position tolerances when:

Accepted Answer

The same datum reference frame is shared and no SEP notation is used

Answer

The simultaneous requirement applies when multiple position callouts reference the same datum reference frame without the SEP (Separately) notation, meaning they must be verified in the same setup.

Question 4

How many tolerance zones exist for each feature in a composite position callout with both PLTZF and FRTZF?

Accepted Answer

Two separate zones — one from each segment

Answer

Each feature must simultaneously satisfy two tolerance zones: the larger PLTZF zone (which locates the pattern) and the smaller FRTZF zone (which controls feature-to-feature relationships).

Question 5

In composite profile of a surface, what does the lower segment control compared to the upper segment?

Accepted Answer

Profile form, orientation, and feature-to-feature location (but not absolute location)

Answer

The lower segment of composite profile controls form, orientation, and the relationship between features, but the tolerance zone can translate/rotate relative to the datum reference frame.

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

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

GD&T Composite Feature Control 3