ASME ASME Geometric Dimensioning and Tolerancing

Question 1

Which ASME standard governs Geometric Dimensioning and Tolerancing (GD&T) in the United States?

Accepted Answer

ASME Y14.5

Answer

ASME Y14.5 is the standard for Geometric Dimensioning and Tolerancing used in US engineering drawings.

Question 2

In GD&T, what does the feature control frame symbol ⊕ represent?

Accepted Answer

Position

Answer

The bullseye symbol (⊕) in a feature control frame represents the position geometric characteristic.

Question 3

What is the purpose of a datum reference frame in ASME Y14.5 GD&T?

Accepted Answer

To establish a coordinate system from which measurements are made

Answer

A datum reference frame establishes the three mutually perpendicular planes from which part features are located and measured.

Question 4

Under ASME Y14.5, what does the modifier ⓜ (circle M) mean when applied to a position tolerance?

Accepted Answer

Maximum Material Condition

Answer

The ⓜ modifier specifies Maximum Material Condition (MMC), meaning the feature has the most material — smallest hole or largest pin.

Question 5

Which GD&T characteristic controls the form of a surface to be within two parallel planes?

Accepted Answer

Flatness

Answer

Flatness controls the form of a surface by requiring all surface points to lie within two parallel planes separated by the tolerance value.

ASME - American Society of Mechanical Engineers Practice Test