Dimensioning includes measurments, notes and symbols

Placement of Dimensions

Dimensioning Diameters

Dimensioning Radii - which do not need their centers located

Dimensioning Radii - when locating the raduis center

Dimensioning Rules
-dimensions should not be duplicated or fiven on a drawing in two different ways.
-dimensions should not be placed in the view where the best shape and true form are shown.
-avoid long extension and leader lines.
-place a dimension between views, especially if it applies to both ciews and will improve clarity
-do not assume that a part is symmetrical. Dimension both sides of a symmetrically shapped part or use the centerline cymbol or not to avoid confusion.
-spacing between dimensions should be consistent within a drawing
-line up dimensions horizontally and vertically where possible.
-avoid crossing dimension lines or leaders where possible.