The leader lines should be used to dimension circle. This helps in identifying true shape as well dimension related to circle. It is advised not to dimension cylinders in views where it is seen as any shape or than circle but should be dimensioned where its cross-section is clearly visible.

It is recommended that a gap of about 1 mm should be kept between extension line and an outline or object boundary by B.I.S. It extends by about 3 mm beyond dimension line.

Dimensions have to be placed where true shape or features are clearly indicated. For example, if re is a cylindrical hole in object, size of cylinder i.e. diameter of base circle should be dimensioned in view where it is seen as a circle and not in view where cylinder is seen as a rectangle.

The standard ratio of height to length of an arrow in dimensioning should be kept only 1:3. Even if re are so many types of arrows like oblique stroke, closed, open small open circle etc. Generally closed and filled arrowhead is widely used and with 1:3 ratio.

The example has unidirectional and chain type of dimension. The dimension figures are arranged horizontally and can only be read from bottom. The dimensions are arranged in a straight line and not in parallel direction.

Short-break lines are continuous, thin and wavy. They are drawn with freehand and are used to show a short-break or irregular boundaries. Long-break lines are thin ruled lines with short zigzags within m.

The standards are made as such that dimension lines should be drawn at least 8 mm away from outlines and from each or. This gives clear, neat appearance in mentioning dimensions in drawing.

All dimensions should be expressed in one unit. Using different units for dimensions will create confusion for observer and re is a chance of misinterpretation. Therefore, using different units should be avoided and a tag ?All dimensions are in mm? should be added above title page.

In aligned system dimension is placed perpendicular to dimension line. The dimensions should be placed near middle and above, but clear of dimension lines.

It is customary to write figures with a height of 3mm to 5mm. This helps in readability of dimension figures. It also makes reading dimensions easy. The thickness of letters is so adjusted that it can read without effort.