Which of the following terms refers to controlling the "shape" of a part?

• A. Orientation
• B. Size
• C. Form
• D. Location

Answer: (C)

The term that refers to controlling the "shape" of a part is "Form." In Geometric Dimensioning and Tolerancing (GD&T), form specifically addresses the actual geometric shape of a feature, distinguishing it from other concepts like size, orientation, and location. Form control ensures that a feature maintains its intended shape, which can be critical for the proper functioning of a part in an assembly.

For example, if a feature needs to be a perfect circle, the form tolerance will define how much deviation from that circle is acceptable. This is essential because if a feature's shape is distorted, it may lead to improper fit or function within an assembly, regardless of its location or size.

Controlling form is fundamental in ensuring parts meet the design specifications, thereby allowing for proper assembly and performance in a mechanical system.