Chapter 7 Orientation Tolerances 295 Copyright Goodheart-Willcox Co., Inc. Orthographic View ∅0.2 Perpendicularity tolerance zone 90° SECTION A-A Meaning Possible orientation of feature axis Datum axis A SECTION B-B No orientation control Model View Goodheart-Willcox Publisher Example 7-12. Specifying a cylindrical perpendicularity tolerance zone.