Engineering Drawing and CAD Flashcards

In CAD, parametric modeling means:

Answer: Model geometry is driven by defined parameters and constraints

Parametric modeling ties geometry to design parameters (dimensions and constraints), so changing a parameter automatically updates the entire model.

A datum in GD&T is:

Answer: A theoretically exact point, axis, or plane used as a reference

A GD&T datum is a theoretically perfect geometric reference (point, line, or plane) established from actual part features to measure other geometric tolerances.

Which line type represents the axis of symmetry in engineering drawings?

Answer: Long chain (dash-dot) line

A centerline (long chain or dash-dot-dash line) indicates axes of symmetry, center points, and paths of motion in engineering drawings.

In ASME Y14.5 GD&T, the Maximum Material Condition (MMC) modifier means:

Answer: The feature contains the most material within its tolerances

MMC refers to the condition where a feature of size contains the maximum amount of material — largest shaft diameter or smallest hole diameter within tolerance.

An isometric view is a type of:

Answer: Pictorial (axonometric) projection

Isometric projection is an axonometric (pictorial) drawing where all three axes are equally inclined to the projection plane at 30°, giving equal foreshortening.

Surface finish (roughness) on a drawing is indicated by:

Answer: A check mark symbol (√) with Ra value

Surface texture is specified using the surface finish symbol (√) with roughness value Ra (arithmetic average) per ASME B46.1 standards.