1. Dimensioning

2. Dimensioning Size description Interchangeability of parts.
Knowledge of manufacturing needed
Drawings should be exactly to size

3. Object of Dimensions Functionality For manufacturing
eliminate calculations
Enough dimensions to fully define part
Not necessarily the dimensions to draw part.

4. Purpose of Dimensions
Linear distance
Angles
Notes

5. Dimensioning
Have gap between part and dimension
Uniform spacing

6. Placement of Dimensions
Smallest dimensions closer to part.
Witness lines extend to the part.
Witness lines should not cross dimensions
Correct
Wrong

7. Placement of Dimensions
Dimensions should not be placed on the part.
Dimensions should be spaced from the part.
Wrong

8. Grouping Dimensions Group dimensions together.
Wrong
Group dimensions together.
Group dimensions between appropriate views.
Correct

9. Superfluous Dimensions
There should only be enough dimensions to define the part.
A feature should only be dimensioned in one view.
it should not be possible to calculate a dimension from other dimensions.
Extra Dimensions
Missing Dimension