ABSTRACT
In both types of control, the feature control frame will appear in a view where the controlled surfaces appear as a straight line.
When used as a surface control, for example, for a planar surface (see Fig. 5-1), the tolerance zone is considered the distance between two parallel lines. The lines are accepted as perfectly straight and a distance apart equal to the tolerance in the feature control frame. Each line element of the considered surface must lie between two parallel lines, which are the allowed tolerance apart shown in the feature control frame. These controlled line elements are inspected in the same plane represented in the view showing the control.
