Specifying a Projected Tolerance Zone for Parallelism of a Plane
When the dimensioned feature is a plane feature, you can define a projected tolerance zone for the Parallelism FCF by selecting the projection zone symbol (the letter P within a circle) from the <PZ> compartment. You can then define the size of the planar zone by typing a value in the <len> compartment.
Selecting the Projected Tolerance Zone
Defining the Projected Tolerance Zone's Size
Projected Tolerance Zone Size as Length / Width - You can type the projected zone's size value as two numbers separated by a forward slash, which represents the length/width of the zone along the major/minor axes of the workplane. So, if your workplane was XY and you typed 10/15, the length of 10 would be along the X axis (major axis) and the width of 15 would be along the Y axis (minor axis). The length and width are measured on the actual plane. The axes of the current active workplane are used only to determine the orientation of the length and width on the actual plane.
Projected Tolerance Zone Size as Diameter - You can also type the projection zone's <len> value as a single number. This is used when the plane is the end of a cylindrical pin. The projection value zone in this case represents the diameter of the planar surface.
Specifying a Projected Tolerance Zone for Parallelism of any Other Feature
When the dimensioned feature is a non-plane feature (for example a cylinder), the projected zone is always a single value and has the same meaning as a projected zone for Perpendicularity, Angularity, or Position.
A Note on Parallelism Evaluation
The evaluation of parallelism is 3-dimensional, regardless of the workplane or the feature being dimensioned.