CAD Specialist Mechanical Design and Engineering Flashcards

In mechanical CAD, what does GD&T stand for?

Answer: Geometric Dimensioning and Tolerancing

GD&T (Geometric Dimensioning and Tolerancing) is a symbolic language used on engineering drawings to define the allowable variation in form, orientation, and location of features.

What is the purpose of a 'datum' in GD&T?

Answer: A theoretically exact reference point, axis, or plane from which measurements are made

A datum is a theoretically exact reference feature (point, axis, or plane) used as the origin from which geometric tolerances and dimensions are measured.

In Inventor or SolidWorks, what is a 'parametric model'?

Answer: A model whose geometry is driven by editable dimension parameters

A parametric model stores design intent through dimensions and constraints, so changing a parameter automatically updates the entire model geometry.

What is a 'bill of materials' (BOM) in mechanical CAD assembly design?

Answer: A structured list of all components, quantities, and part numbers in an assembly

A BOM (Bill of Materials) is a structured table listing every part, sub-assembly, quantity, and part number that makes up a product assembly.

In mechanical drafting, what does a 'section view' show?

Answer: The interior features of a part as if it were cut open along a cutting plane

A section view exposes the internal features of a part by showing it as if it were cut along a defined cutting plane, revealing interior geometry.

What is the function of 'mating constraints' or 'mates' in a CAD assembly?

Answer: Defining geometric relationships that position and constrain parts relative to each other

Mates (or assembly constraints) define how parts relate to one another — coincident, concentric, flush, etc. — to correctly position components in an assembly.