What are the types of lines used in technical drawing?

1. Visible lines: These are solid lines used to represent the edges and outlines of objects in a technical drawing.

2. Hidden lines: These are dashed lines used to represent edges or features that are not visible in the current view of the object.

3. Center lines: These are long, short-dashed lines used to indicate the center of a circle, arc, or symmetrical object.

4. Extension lines: These are thin, solid lines used to indicate the boundaries of a dimension or measurement.

5. Dimension lines: These are thin, solid lines with arrowheads at each end used to indicate the size or distance of an object or feature.

6. Cutting plane lines: These are thick, long-dashed lines used to indicate where an object is cut in a sectional view.

7. Phantom lines: These are long, short-dashed lines used to show alternate positions or repeated details in a technical drawing.

8. Break lines: These are thick, jagged lines used to indicate where a part of an object has been removed for clarity in a drawing.

Construction Lines:

- Dimension and Leader Lines: Extend from the feature or object being dimensioned to the dimension value.
- Projection Lines: Extend perpendicularly from an object to represent its true shape or size.
- Center Lines: Divide symmetrical objects and indicate centers of circles, arcs, and ellipses.
- Grid Lines: Used to organize and align objects within a drawing.
- Tangent Lines: Touch an arc or circle at one point and are perpendicular to a radial line.
- Witness Lines: Indicate the extension of a line that is not fully visible.

Outline Lines:

- Visible Lines: Show the edges of an object that are visible from the given view.
- Hidden Lines: Represent edges of an object that are not visible from the given view.
- Center Lines: Divide symmetrical parts.
- Thin Lines: Outline contours of objects but not their boundaries.

Cross-Section Lines:

- Section Lines: Represent the cut surface of an object in a section view.
- Break Lines: Indicate that a portion of an object has been omitted due to lack of space.
- Extension Lines: Extend the cut surface of an object beyond its actual boundary to show the full shape.

Dimension Lines:

- Linear: Measure the length or width of an object.
- Radius: Measure the radius of a circle or arc.
- Diameter: Measure the diameter of a circle.
- Angular: Measure the angle between two lines.

Other Lines:

- Extension Lines: Connect arrows for leadering.
- Pattern Lines: Represent materials or finishes.
- Welding Symbols: Indicate welding details.
- Electrode Symbols: Indicate electrical components.