【Daily Question No. 122】December 30, 2018

The three elements used to indicate dimensions in mechanical drawing are dimension lines, extension lines and arrows, and dimension numbers.

Dimension lines, extension lines, dimension figures

Dimension lines, dimension boundaries, and dimension numbers.

Length aligned, height even, width equal

The three elements required to indicate a complete dimension in mechanical drawing are the dimension line, the dimension boundary, and the dimension text.

Dimension lines, dimension boundaries, and dimension numbers

Dimension line, dimension line extension, dimension figure

The three elements of a dimension are the dimension line, the dimension boundary, and the dimension text

The three elements of dimensioning: dimension lines, extension lines, and dimension figures. 1. Dimension figures: (1) The numbers indicating linear dimensions should generally be written above the extension line; it is also acceptable to write them at the break in the extension line. (2) Linear dimension numbers should generally be indicated in the direction shown in Figure 1-15a, and efforts should be made to avoid marking dimensions within a 30° range around the illustration; if this cannot be avoided, they may be marked in the manner shown in Figure 1-15b. 2. Dimension lines: Dimension lines are drawn as thin solid lines to indicate the direction of the indicated dimension. 3. Dimension lines: (1) Dimension lines are drawn as thin solid lines, and they should originate from the contour lines, axes, or symmetry axes of the figure; alternatively, these contour lines, axes, or symmetry axes can themselves be used as dimension lines ； (2) The dimension line should generally be perpendicular to the dimension line and extend slightly beyond it (usually 3–4 mm is appropriate) ； Under special circumstances, they need not be perpendicular, but the two dimension lines must be parallel to each other.

Dimension lines, dimension boundaries, and dimension numbers