 Elements of dimensioning should be drawn with finer(thinner) lines than the edges of the object (thicker)
 It is not necessary to dimension all the edges of an object (the minimum number of dimensions required to understand the drawing).
Elements of dimensioning:Dimension: It is the number that show the real measurement of the object.
 Normally in millimetres.
 Must be in the centre (middle) of, and parallel to the dimension line.
 Must be above horizontal dimension lines and left of vertical dimension lines.
 If there is not space on the dimension line to put the dimensions, they can be placed on a leader line.
Dimension lines: Must be parallel to and the same length as the edge (side) of the object.
 Must be placed outside of the object.
 If there is a smaller object inside the main one you can put dimension lines inside the object.
 We cannot use the edges of the object as dimension lines.
 Dimension lines should not cross other lines.
 Dimension lines should be situated at least 8 mm away from the edge of the object.
 The following dimension lines should be situated at least 5 mm away from other.
Symbols at the end of the dimension lines: They are usually arrowheads or oblique stroke (slashes) or if there is not space to put arrowhead dots.
 If the arrows or dimensions do not fit on the dimensiones line, they should go outside the line.
Extension lines; It is a line perpendicular to the dimension line.
 Extend for 2mm on each side of the dimension lines.
Leader lines; This shows a note, a number, data related to the object.
Symbols; Before the dimension number.
 Radius: R Diameter: ∅ Square: □ Sphere: radio SR diameter S∅
 Angles are dimensioned with arcs.
 Radii and diameters can be dimensioned inside a circle or indicated by an arrow at the point of contact with the circumference.
