The document discusses various geometric dimensioning and tolerancing (GD&T) concepts, focusing on straightness, flatness, circularity, and cylindricity tolerances. Each section explains the definition, application, and influence of Rule #1 on the respective tolerances, along with significant questions related to verification. The document highlights that these tolerances are essential for defining permissible deviations in surface profiles and geometries.

1. Geometric Dimensioning and
Tolerancing (GD&T)
Form Tolerance

2. Straightness Tolerance
• A straightness tolerance is a geometric
tolerance that defines the straightness
deviation permitted on individual surface
elements or on a derived median line.

5. Types of Straightness Deviations

6. Rule#1’s Effect on Straightness Deviation of
a Derived Median Line

7. Applications of Straightness Tolerances

8. Straightness Applied to a Surface

9. Straightness Tolerance Application

10. Straightness Tolerance Applied to a
Feature of Size (FoS)

11. Significant Questions on Straightness Tolerance

12. • Verifying a
straightness Tolerance
Zone

13. Straightness Tolerance (at MMC)
applied to a FoS

14. Flatness
• Flatness Tolerance is a geometric tolerance
that defines the allowable flatness deviation
permitted on a planar surface or derived
median plane.

15. How Rule#1 affects the Flatness on a Surface

16. Flatness applied to a Surface

17. Flatness @MMC applied to a FoS

18. Significant Questions on Flatness Tolerance

19. Verifying a Flatness Tolerance applied to a Planar
Surface

20. Verifying Flatness Tolerance @ MMC applied to a FoS

21. Circularity Tolerance
• A circularity tolerance is a geometric tolerance that
limits the circularity deviation (radial deviation
between highest and lowest points) on individual
circular elements. A circularity tolerance:
– Is one of the four direct form tolerances.
– Never uses a datum feature reference.
– Can only be applied to a single feature with circular cross
sections (eg sphere, cylinder, cone, etc).
– Applies to each circular element of a surface
independently.

22. Rule # 1 Effects on Circularity
Tolerance

23. Circularity Deviations

24. Circularity Tolerance applied to a
Surface

25. Circularity Tolerance and its Tolerance
Zone

26. Significant Questions Applied to a
Circularity Tolerance

27. Roundness Gage

28. Cylindricity Tolerance
• A cylindricity tolerance is a geometric tolerance
that defines the deviation permitted on a
cylindrical surface. A cylindricity tolerance
applies along the entire cylindrical surface
simultaneously.
• A cylindricity tolerance:
– Is one of the four direct form tolerances
– Never uses a datum feature reference
– Can only be applied to a single cylindrical feature
– Applies to the entire surface simultaneously.

29. Cylindricity Tolerance Zone may contain any
Combination of these Form Deviations

30. Cylindricity Tolerance and Tolerance Zone

31. Rule #1 effects on Cylindricity Deviation of a Surface

32. Significant Questions applied to a Cylindricity Tolerance