Exam 27: Geometric Tolerances - Datums

Allowable variations in basic dimensions are established by tolerances in the feature control frame.

The symbol that consists of a capital letter enclosed in a box is:

A geometric control symbol, tolerance, and datum that apply to a feature's specification are contained in a feature control frame.

More than one datum plane may be used to establish positional relationships on a part.

Geometric dimensioning controls:

Primary datum planes are developed by establishing ________ point(s)of contact on the primary datum surface.

A datum axis is the theoretical exact centerline of a datum cylinder.

Geometric characteristic symbols (or feature control symbols)include symbols for:

The perfect location of a point, line, or surface is:

A datum feature is a real physical part of the object that may have surface variations.

A symbol for a circular datum target includes:

A basic dimension is:

In a feature control frame, the datum appears before the tolerance.

For castings or other parts that have irregular surfaces, these are often used to establish the position of the part for manufacturing or inspection purposes:

The intentional difference in size between mating parts is called:

A datum cylinder may be internal (a round hole)or external (a round shaft).

The actual part surface or feature used to establish a datum is a: