GD&T - Geometric Dimensioning and Tolerancing Form and Orientation Tolerances Questions and Answers

Question 1

Which of the following geometric tolerances is classified as a form tolerance and does NOT require a datum reference?

Accepted Answer

Flatness

Answer

Perpendicularity

Answer

Angularity

Answer

Parallelism

Question 2

A feature control frame for a surface specifies an angularity tolerance. What is the shape of the tolerance zone?

Accepted Answer

Two parallel planes oriented at a basic angle to a datum

Answer

A cylindrical zone around a theoretical axis

Answer

A conical zone originating from a datum vertex

Answer

The space between two concentric circles on the surface

Question 3

A drawing calls out a perpendicularity tolerance for the axis of a hole. A diameter symbol (⌀) is included before the tolerance value in the feature control frame. What does this indicate?

Accepted Answer

The tolerance zone is a cylinder within which the axis of the hole must lie.

Answer

The tolerance applies to the circularity of the hole.

Answer

The measurement must be taken using a cylindrical gage pin.

Answer

The tolerance only applies at the maximum material condition of the hole.

Question 4

In a scenario where a pin must assemble into a hole, applying a perpendicularity tolerance at Maximum Material Condition (MMC) to the pin offers what primary advantage?

Accepted Answer

It allows for a potential increase in the geometric tolerance, known as bonus tolerance, as the pin's size departs from MMC.

Answer

It guarantees the pin will have a perfect surface finish.

Answer

It minimizes the manufacturing cost by allowing a larger size tolerance.

Answer

It ensures the pin is perfectly straight regardless of its size.

Question 5

What is the key difference between the application of a flatness tolerance and a parallelism tolerance to a planar surface?

Accepted Answer

Parallelism requires a datum reference, while flatness does not.

Answer

Flatness controls surface waviness, while parallelism controls roughness.

Answer

Flatness can be modified by MMC, but parallelism cannot.

Answer

The tolerance zone for flatness is cylindrical, while for parallelism it is planar.

Question 6

If a perpendicularity tolerance is specified for a planar surface without any material condition modifiers in the feature control frame, what is the default condition that applies?

Accepted Answer

Regardless of Feature Size (RFS)

Answer

Least Material Condition (LMC)

Answer

Maximum Material Condition (MMC)

Answer

Projected Tolerance Zone