Feature Dimensions
Dimensioning Simple Features
Different types of features require unique methods of dimensioning.
- A circle is dimensioned by its diameter and an arc by its radius using a leader line and a note.
- The depth of a blind hole may be specified in a note and is the depth of the full diameter from the surface of the object.
- If a hole goes completely through the feature and it is not clearly shown on the drawing, the abbreviation “THRU” follows the dimension.
- If a dimension is given to the center of a radius, a small cross is drawn at the center. Where the center location of the radius is unimportant, the drawing must clearly show that the arc location is controlled by other dimensioned features such as tangent surfaces
- A complete sphere is dimensioned by its diameter and an incomplete sphere by its radius.
