1. Dimensioning
Dimensioning

2. Dimensioning Overview:
Dimensions describe the size and location of features of an object.
The correct placement of dimensions is strictly prescribed by an extensive list of drawing conventions.

3. Dimensioning Lines used in dimensioning:
Dimension line: A dimension line is a thin, dark line terminated by arrowheads and indicates the extent of the dimension.
Extension line: An extension line is a thin, dark line that extends from a point on the drawing to which a dimension refers.

4. Dimensioning
Spacing of dimension lines should be uniform throughout the drawing. The dimension line nearest the object should be spaced at least 3/8” away from the object.
All other dimension lines should be spaced at least 1/4” apart.
A 1/16” gap is left where the extension line would join the object outline and extends 1/8” past the outermost dimension line.

5. Dimensioning Center Lines:
Center Line: A center line is a thin, dark line composed of alternate long and short dashes and is used to represent axes of symmetry, locate holes, and to denote centers.
Center lines are commonly used as extension lines.
When a center line crosses over an object line, it crosses the object line without a gap.

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10. Dimensioning Mr. Ference’s rules for dimensioning:
Spacing for all dimension lines should be uniform and consistent.
Never cross a dimension line.
Place dimensions where the feature shows both true size and true shape.
Never dimension to a hidden line.

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