1. 7 Orientation Tolerances

2. Identify, apply, and interpret orientation tolerances. • Complete orientation tolerance specifications including one or two datum feature references. • Explain the effects of material condition modifiers when orientation tolerances are applied to features of size.

3. Calculate the virtual condition for internal and external features of size to which an orientation tolerance is applied. • Complete tolerance specifications that include orientation and form requirements on a single feature.

4. Orientation Tolerances • Orientation tolerances specify the allowable parallelism, perpendicularity, or angularity variation of a feature relative to one or more datums. • They are specified using a feature control frame, and may be applied to surfaces and to features of size.

5. Orientation Tolerance Categories • Parallelism • Perpendicularity • Angularity

6. Orientation Tolerance Symbols

7. Feature Control Frames

8. Virtual Condition • MMC applied to feature of size establishes a virtual condition • Virtual conditions of mating parts are equal or provide a clearance • Internal features • Vc = MMC – orientation tolerance • External features • Vc = MMC + orientation tolerance

9. Feature Center Plane and Feature Axis

10. Parallelism Interpretation—Surface • Orientation between flat surface and datum plane may be specified with parallelism tolerance • Size tolerance between parallel flat surfaces establishes orientation

11. Parallelism Interpretation—Cylinder • Orientation between feature axis and datum plane or datum axis may be specified with parallelism tolerance

12. Perpendicularity on a Surface • 90° dimension not required • Tolerance must be specified • Feature control frame on extension line or leader to the surface • Must reference a datum

13. Face Surface Elements on a Shaft

14. Perpendicularity Applied to Features of Size • Establishes control of the axis or center plane of the feature, or may be defined as control within the virtual condition • Feature control frame must be associated with the size dimension • May be adjacent to dimension • May be attached to dimension line

15. Perpendicularity of a Hole—Axis Interpretation • Must be controlled relative to a datum feature • The perpendicularity tolerance value is diameter of a cylindrical zone

16. Controlling Perpendicularity of a Center Plane—Drawing

17. Controlling Perpendicularity of a Center Plane–Possible Condition #1

18. Controlling Perpendicularity of a Center Plane—Nonparallel Sides

19. Angularity on Surfaces • Tolerances always referenced to one or more datums • Feature control frame attached to leader or extension line

20. Tangent Plane

21. Combined Form and Orientation Tolerances • Control orientation to one value and form to a smaller value • Orientation also controls form when applied to a surface