Lines
Representation of line A/q to standard
- A,B,C,D,E,F,G,H,J,K
- A,
- B,
- C,
- D,
- E,
- F,
- G,
- H,
- J,
- K
Classification of lines
Object line
- Visible/Object Lines: Dark, thick lines (typically 0.6 mm thick).
- Represent the visible edges and outlines of objects, defining their contours and features
Construction (Imaginary) Line
- Construction lines, also known as imaginary lines, are lightly drawn lines used as temporary guides while creating a drawing.
- Construction lines are sometimes erased in the final drawing
Dimension line
- Dimension Lines: Thin continuous lines with arrowheads at the ends.
- Use: Connect the feature to be dimensioned with the dimension value, providing size information.
Extension line
- Extension Lines: Thin continuous lines.
- Use: Extend from the feature to the dimension line, ensuring clarity in measurement
Leader line
- Leader Lines: Thin continuous lines.
- Use: Connect notes or dimensions to specific features on the drawing
section line
- Section Lines: Thin lines drawn at a 45-degree angle.
- Use: Represent the surface that has been cut in a sectional view, typically shown as hatching.
break line
- Break Lines: Various types, including short break lines (thick wavy lines), long break lines (thin lines), and cylindrical break lines.
- Use: Indicate that a portion of an object has been removed for clarity or to shorten the drawing
hidden line
- Hidden Lines:: Light, narrow, short, and dashed lines (typically 0.3 mm thick).
- Use: Indicate edges or boundaries that are not visible from the current view, helping to clarify hidden features
center line
- Center Lines: Thin lines with alternating long and short dashes.
- Use: Indicate the center of circles, arcs, or symmetrical parts.
cutting plane line
- Cutting Plane Lines: Thick lines with arrows.
- Use: Indicate the plane where a section view is taken
Phantom Lines:
- Phantom Lines: Thin lines composed of long dashes alternated with pairs of small dashes.
- Use: Indicate alternate positions of moving parts, adjacent positions, or repeated details
Lettering and Numbering
- Lettering is generally done in uppercase (capital letters)
- Inclined letters slope at about 75° with the horizontal.
- The ratio of height to width for most letters is 6:5
