Joshua Nava Arts

Geometric Tolerancing

Geometric Tolerancing is used Things like:

•Straightness •Flatness •Circularity •Cylindricity

•Angularity

Geometric Tolerances are shown on a to specify the shape of features. •Profiles

•Perpendicularity •Parallelism •Concentricity •And More...

drawing with a feature control frame.

The Feature Control Frame

This feature control frame is read as: "The specified feature must lie perpendicular within a tolerance zone of 0.05 diameter at the maximum material condition, with respect to datum axis C. In other words, this places a limit on the amount of variation in perpendicularity between the feature axis and the datum axis. In a drawing, this feature control frame would accompany dimensional tolerances that control the feature size and position.

Geometric Characteristic Symbols

FIG. 3-1 GEOMETRIC CHARACTERISTIC SYMBOLS

A feature control frame gives information about geometric tolerances on the feature. 15

Straightness Example

THIS ON THE DRAWING

MEANS THIS (a)

0.02 wide tolerance zone

016.00 MMC

— 0.02 wide tolerance zone

016.00 MMC

Each longitudinal element of the surface must lie between two parallel lines (0.02 apart) where the two lines and the nominal axis of the part share a common plane. The feature must be within the specified limits of size and the boundary of perfect form at MMC (16.00).

Note: Waisting (b) or barreling (c) of the surface, though within the straightness tolerance, must not exceed the limits of size of the feature.

Straightness at MMC

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