Dimensioning Practice: Definition, Elements of dimensioning, Types of arrow heads and leader line with text is here for CBT Exam preparation.
Definitions related to dimensioning
Dimension: It is a numerical value expressed appropriate unit of measurement and indicated graphically on technical drawings with lines, symbols and notes.Elements of dimensioning
- Extension line
- Dimension line
- Arrow heads
- Leader line
Extension line: It is a thin line projecting from the feature and extending beyond the dimension line.
It is normally perpendicular to the feature being dimensioned, but may be drawn obliquely as shown for dimensioning tapers, parallel to each other.
Dimension line: These are thin continuous lines, terminated at ends by arrow heads, dots or oblique lines touching the extension line.
Dimension line may cut or cross another dimension line where there is no other way. Dimension to the hidden lines be avoided.
Types of arrow heads
- Open arrow heads
- Closed arrow heads
- Closed and fillet arrow heads
- dots or oblique arrow heads
Leader line: It is a thin continuous line. It connects a note or dimension with the features to which it applies.
Termination and Origin indication: The size of the terminations (arrow heads/oblique strokes) shall be proportional to the size of the drawing. Only one style of arrow head shall be used on a single drawing. However, where the space is too small for the arrow heads, it may be substituted by a dot or by an oblique line. Arrow heads are drawn as short lines forming barbs at any convenient included angle between 15° and 90°. They may be open, closed or closed and filled in. Oblique strokes drawn as short line inclined at 45°.
ED 1st Year Other Topics for Electrical Trades
Electrical Trades - Electrician, Wireman, Electroplater, Lift & Escalator Mechanic, Electrician Power Distribution. Select Engineering Drawing 1st Year topic from below.