What type of tolerance is used to control the shape of features such as straightness and flatness?

Form tolerance is specifically designed to regulate the shape of features on a part. It focuses on the geometric characteristics such as straightness, flatness, circularity, and cylindricity. This type of tolerance ensures that the actual shape of a feature adheres to a defined ideal shape, thus maintaining quality and functionality within the engineering design specifications. By applying form tolerance, engineers can ensure that components not only fit together properly but also perform their intended function reliably.

In contrast, profile tolerance addresses the contour of surfaces and can have more complex requirements, while location tolerance deals with the positioning of features relative to each other. Orientation tolerance ensures features are aligned correctly, such as being perpendicular or parallel to one another. Each of these tolerance types has a distinct purpose, but for controlling the shape of features, form tolerance is the most appropriate choice.