General Rules of Dimensioning Place dimensions between views whenever possible Dimension the most descriptive part or view of the item Extension lines may cross object lines, but do not break them Dimension inside a recess if it improves communication

Dimension to visible lines only, not to hidden lines Extension lines may cross each other if necessary, but dimension lines should not cross Keep dimensions off the objects Dimension true length lines and surfaces only Do not use a dimension line for an extension line Place running dimensions in direct line with each other when possible