Co ordinate tolerancing vs Geometric dimensioning and tolerancing - T slot example

Mufaddal Rasheed Author

Difference between Co ordinate tolerancing and Geometric tolerancing with example. Why GD&T is better ?

Difference between Co ordinate tolerancing and Geometric tolerancing with T slot example

The T part slides to and fro on the brown part .

Drawing with conventional dimensioning and tolerancing

Drawing with GD&T :

Differences and why GD&T drawing is better :

There are no Datums applied , which makes I difficult to relate the features and establish relative geometric control.
All dimensions indicate size and there is no differentiation between Size and position control
The orientation - perpendicularity is key to application. In the first drawing there is an implied 90 degree angle but there is no explicit mention of perpendicularity control , whereas the GD&T drawing explicitly mentions that perpendicularity should be controlled with a tolerance zone of 0.2 .
The Flatness controls the form of the sliding faces.
The position of width 50 is controlled and ensured symmetric to the datum B

To learn more about GD&T have a look at this course