GD&T - Geometric Dimensioning and Tolerancing Profile Tolerancing Applications Questions and Answers

Question 1

A designer needs to control the form of a complex, curved surface on a casting, but its location and orientation relative to other features are not critical.
Which of the following GD&T callouts is most appropriate?

Accepted Answer

Profile of a surface with no datum references.

Answer

Profile of a surface with datum references A, B, and C.

Answer

Position tolerance applied to the surface.

Answer

Flatness tolerance applied to the surface.

Question 2

On an engineering drawing, two separated, non-continuous surfaces must be treated as a single plane. Which is the best GD&T application to control this coplanarity requirement?

Accepted Answer

Specifying a profile of a surface tolerance across both features.

Answer

Applying a separate flatness tolerance to each surface.

Answer

Using a parallelism tolerance referencing a common datum.

Answer

Controlling the distance between the surfaces with a size dimension.

Question 3

An engineer has specified both a profile of a line and a profile of a surface tolerance on the same airfoil feature. What is the typical relationship between these two controls?

Accepted Answer

The profile of a line tolerance is typically tighter than the profile of a surface tolerance.

Answer

The profile of a line tolerance is typically larger than the profile of a surface tolerance.

Answer

The two tolerances are always equal.

Answer

The profile of a surface tolerance controls cross-sections, while the line profile controls the entire surface.

Question 4

A part has a complex contour defined by basic dimensions. A composite profile tolerance is applied. What is the primary function of the lower segment in the feature control frame?

Accepted Answer

To refine the orientation and/or form of the profile within the larger tolerance zone defined by the upper segment.

Answer

To control the location of the feature relative to the datums.

Answer

To apply a bonus tolerance based on the feature's size.

Answer

To override the upper segment entirely, making it informational only.

Question 5

Which of the following is the key difference between Profile of a Line and Profile of a Surface?

Accepted Answer

Profile of a Line is a 2D tolerance controlling individual cross-sections, while Profile of a Surface is a 3D tolerance controlling the entire surface.

Answer

Profile of a Line applies only to flat surfaces, while Profile of a Surface applies to curved surfaces.

Answer

Profile of a Surface is a 2D control, while Profile of a Line is a 3D control.

Answer

Profile of a Line must always reference datums, whereas Profile of a Surface does not.

Question 6

Under which scenario can a profile of a surface tolerance be used to control size, form, orientation, AND location simultaneously?

Accepted Answer

When applied to a feature defined by basic dimensions and related to a datum reference frame.

Answer

When applied to a feature of size with the MMC modifier.

Answer

When applied to a surface with no datum references.

Answer

When used in a composite feature control frame's lower segment.

A designer needs to control the form of a complex, curved surface on a casting, but its location and orientation relative to other features are not critical.Which of the following GD&T callouts is most appropriate?

A designer needs to control the form of a complex, curved surface on a casting, but its location and orientation relative to other features are not critical.
Which of the following GD&T callouts is most appropriate?