Deck 40: The Datum Reference Frame

Question 1

When checking the accuracy of a flat surface against a datum surface, there will theoretically be more than three points on the flat surface touching the datum surface (gage).

Answer 1

False

Question 2

When only a part of a surface is to be designated as a datum, a ____ line drawn parallel to the surface is used to indicate the portion of the surface acting as the datum.

A) center
B) chain
C) visible
D) cutting-plane

Answer 2

B

Question 3

The three types of datums are primary, secondary, and ____________________.

Answer 3

tertiary

Question 4

Another name for a three-plane datum system is __________________________________________________.

Question 5

If a part is brought into contact with a secondary plane while lying on a primary plane, it will theoretically touch a minimum of ____ points.

A) two
B) three
C) one
D) four or more

Question 6

When a chain line is used to designate a datum, its length must be dimensioned.

Question 7

A datum feature is a feature of a part which is used to establish the location of a datum.

Question 8

A surface plate can be used as a primary datum for a part with a flat surface.

Question 9

Geometric tolerances, such as straightness and flatness, refer to unrelated lines and surfaces and generally relate to datums.

Question 10

When a part is touching primary and secondary datum planes and comes in contact with a tertiary plane, it theoretically touches the tertiary plane in ____.

A) four or more points
B) three points
C) two points
D) one point

Question 11

A point, axis, or plane from which dimensions are measured, or to which geometric tolerances are referenced, is a ____________________

Question 12

Datums are exact geometric points, axes, or ____________________, each based on one or more datum features of the part.

Question 13

The datum feature symbol is ____.

A)
B)
C)
D)