ALPHABET OF LINE

1. The
ALPHABET
of
L I N E S

2. ALPHABET OF LINES
The different lines and line symbols
used on drawings form a kind of
graphic alphabet commonly known as
the alphabet of lines. Two line
widths-thick and thin-are generally
used. Drawings are easier to read
when there is good contrast among
different kinds of lines. All lines must
be uniformly sharp and black.

3. Visible Object Lines
are thick dark solid (unbroken)
lines that are used on
drawings to indicate the edges
and details of an object.

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1. Phantom 2. Section 3. Hidden 4. Cutting/viewing
5. Leader 6. Hidden 7. Center 8. Visible/object
9. Extension 10. Break 11. Visible/object
12. Section 13. Extension 14. Break 15. Dimension

5. Hidden Lines are thin dashed
lines used to indicate a
surface, edge, or contour of an
object that cannot be seen, or
is hidden from view.

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1. Phantom 2. Section 3. Hidden 4. Cutting/viewing
5. Leader 6. Hidden 7. Center 8. Visible/object
9. Extension 10. Break 11. Visible/object
12. Section 13. Extension 14. Break 15. Dimension

7. Center lines are thin lines made
up of alternating long and short
dashes. They are used to indicate
the center of symmetrical
features, such as circles or arcs.
They are used as an aid in
dimensioning.

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A 4
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1. Phantom 2. Section 3. Hidden 4. Cutting/viewing
5. Leader 6. Hidden 7. Center 8. Visible/object
9. Extension 10. Break 11. Visible/object
12. Section 13. Extension 14. Break 15. Dimension

9. Section Lines are thin “cross
hatching” lines used in
sectional views to symbolize
different parts of an object or
different materials from which
an object is manufactured.

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1. Phantom 2. Section 3. Hidden 4. Cutting/viewing
5. Leader 6. Hidden 7. Center 8. Visible/object
9. Extension 10. Break 11. Visible/object
12. Section 13. Extension 14. Break 15. Dimension

11. Dimension, Extension and Leader Lines
are thin lines used for dimensioning
purposes. Dimension and leader lines
generally end with arrow heads and are
accompanied by a number indicating a
size or location dimension.

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1. Phantom 2. Section 3. Hidden 4. Cutting/viewing
5. Leader 6. Hidden 7. Center 8. Visible/object
9. Extension 10. Break 11. Visible/object
12. Section 13. Extension 14. Break 15. Dimension

13. Cutting Plane or Viewing Plane Lines
are very thick lines that indicate where an
imaginary cutting plane passes through
an object, for viewing or sectioning
purposes. Arrowheads on both ends of
the line point toward the surface to be
viewed.

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1. Phantom 2. Section 3. Hidden 4. Cutting/viewing
5. Leader 6. Hidden 7. Center 8. Visible/object
9. Extension 10. Break 11. Visible/object
12. Section 13. Extension 14. Break 15. Dimension

15. Break Lines are used to shorten
a view, or to eliminate repetitive
details when an entire view is not
necessary. Short break lines are
thick wavy freehand lines. Long
break lines are thin straight zig-
zags.

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1. Phantom 2. Section 3. Hidden 4. Cutting/viewing
5. Leader 6. Hidden 7. Center 8. Visible/object
9. Extension 10. Break 11. Visible/object
12. Section 13. Extension 14. Break 15. Dimension

17. Phantom Lines are thin lines
used to indicate alternate
positions of moving parts, lines
of motion, adjacent parts and
repetitive details.

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1. Phantom 2. Section 3. Hidden 4. Cutting/viewing
5. Leader 6. Hidden 7. Center 8. Visible/object
9. Extension 10. Break 11. Visible/object
12. Section 13. Extension 14. Break 15. Dimension

19. THE END