GD&T Symbols and Rules 5

Question 1

Which of the following best describes the 'unilateral' profile tolerance symbol introduced in ASME Y14.5-2009?

Accepted Answer

A 'U' in a circle with a value indicating how much of the zone shifts outside the true profile

Answer

A single arrow pointing inward on the leader line

Answer

The letter 'U' placed after the tolerance value without a circle

Answer

A dashed outline on one side of the profile

Question 2

What is the key difference between concentricity and coaxiality in modern GD&T practice (ASME Y14.5-2018)?

Accepted Answer

Concentricity controls derived median points; coaxiality controls the axis using MMC/LMC modifiers

Answer

Concentricity is used for cylindrical features only; coaxiality for any shape

Answer

Concentricity requires two datums; coaxiality requires one

Answer

They are identical — one term replaced the other

Question 3

A straightness tolerance applied to the surface of a cylinder (not its axis) creates a tolerance zone that is:

Accepted Answer

Two parallel lines on the surface in the direction of measurement

Answer

A cylinder coaxial with the feature

Answer

Two coaxial cylinders

Answer

A 3D envelope around the entire feature

Question 4

Which GD&T symbol is used to indicate that a dimension is for reference only and does not govern production or inspection?

Accepted Answer

Parentheses around the dimension value

Answer

A rectangular box around the dimension

Answer

The letters 'REF' underlined

Answer

An asterisk next to the value

Question 5

The 'statistical tolerance' symbol (ST) in a feature control frame indicates that the tolerance:

Accepted Answer

Is valid only when statistical process controls are in use during manufacturing

Answer

Is calculated from a statistical distribution of measurements

Answer

Applies to a sample of parts, not every part

Answer

Is a bonus tolerance granted automatically

Question 6

In a GD&T position callout for a pattern of holes, the 'simultaneous requirement' means:

Accepted Answer

All features in the pattern are located relative to the same datum reference frame in one setup

Answer

Each hole is inspected separately in its own setup

Answer

The position tolerance applies simultaneously to both MMC and LMC

Answer

All holes must be drilled at the same time during manufacturing

Question 7

Which of the following is the correct GD&T symbol for 'total runout'?

Accepted Answer

Two arrows pointing in opposite directions along a surface line

Answer

A single curved arrow

Answer

A circle with a cross inside

Answer

Two concentric circles