The document presents an overview of engineering graphics concepts including: 1) Types of lines used in technical drawings such as visible, hidden, center, and cutting plane lines. 2) Guidelines for lettering sizes and styles on drawings. 3) Methods for dimensioning drawings including terminology, arrowhead styles, and arrangement of dimensions. 4) Standards for technical drawings in India published by BIS in SP 46 for educational institutions. 5) A step-by-step process for drawing an ellipse using the concentric circle method.

1. Engineering Graphics
Presents BY
A.S.VAGH
M.Tech (IPED) , B.E. Mechanical, PGDIM
E-mail Id: asvagh@india.com

2. Lines
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3. 1
2
3 4
5
6
7
8
9
10
14
13
12 11
Viewing-plane line
Extension line
Dimension Line Center Line
Hidden Line
Break Line
Cutting-plane Line
Visible Line
Center Line (of motion)
Leader
VIEW B-BSECTION A-A
Section Line
Phantom Line
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4. Horizontal Lines
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5. Vertical Lines
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6. Inclined Lines
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8. Parallel Lines
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9. Perpendicular Lines
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10. Circles and Arcs
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11. Drawing a circle of a given
diameter with a compass
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12. Use of the French Curve
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13. Guidelines for Lettering
 For uniformity, all letters should be the same height,
proportion and inclination. A necessary tactic for
maintaining uniformity is the use of guidelines.
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14. Guidelines for Lettering
 Ascender is the part of the lowercase letter that extends
above the body of the letter.
 Descender is the part of the lowercase letters that
extends below the body letter.
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15. Lettering
 Writing titles, dimensions, notes and other important
particular on a drawing is called lettering.
 Lettering should be done properly in clear,
understandable & uniform style.
 It should be in plain & simple style so that it could be
done free hand & speedily.
 Note: Use of drawing instruments in lettering takes
considerable time and hence, it should be avoided
efficiency in the art of lettering can be achieved by careful
& continuous practice.
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16. Lettering
 The size of letter is specified by its height.
 Generally the ratio of height to width for most of the
capital letters are taken as 6:5 and for most of the
lower case letters are taken as 4:4.
 Main letter are generally written in 10 mm to 12 mm
 Subtitle is written in 3 mm to 6 mm
 Notes, Dimension fig etc. written in 3 mm to 4 mm.
 Space between the words is generally 2 to 5 mm in
lettering.
 Inclined latter write in an inclination of 750.
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17. Lettering
1) Single Stroke Latter
a) Vertical
b) Inclined
2) Gothic Letter
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18. Lettering
1) Single Stroke Latter -Vertical
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19. Lettering
1) Single Stroke Latter -Vertical
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20. Lettering
1) Single Stroke Latter -Vertical
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21. Lettering
1) Single Stroke Latter -Vertical
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22. Lettering
1) Single Stroke Latter - Inclined
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23. Dimensioning
 Every drawing, whether a scale drawing or a freehand
drawing, besides showing the true shape of an object,
must supply its exact length, breadth, height, sizes and
positions of holes, grooves etc. and such other details
relating to the manufacture of that object. Supplying
this information on a drawing is called Dimensioning.
 Lines, figures, numerals, symbols, notes etc. are used
for this purpose.
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24. Dimensioning terms & notations
 Dimension line: Thin continuous line. It is terminated
by arrowheads touching the outline, extension lines
or Centre lines.
 Extension line: Thin continuous line drawn in
extension of an outline. It extend by about 3 mm
beyond the dimension line.
 Arrow head: Placed at each end of dimension line.
Touch outline, extension line or Centre line. Length
of arrowhead should be three times it max width. The
space betn them is nearly filled up.
 Leader: Thin continuous line connecting a note or
dimension fig with future.
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25. Dimensioning terms & notations
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26. Arrow heads
1. Open (900)
2. Open (200)
3. Closed
4. Closed and Filled
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27. Method of Indicating Dimension
(Aligned System)
Oblique Angular
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28. Method of Indicating Dimension
(Uni-directional System)
Angular
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30. Dimensions
Shape Identification Symbols
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31. Arrangement of Dimensions
1. Chain Dimension:
2. Parallel Dimension:
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32. Arrangement of Dimensions
3. Super Imposed Continuous (Less Space) Dimension:
4. Combined (Chain & Parallel) Dimension:
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33. Arrangement of Dimensions
5. Co-ordinate Dimension:
6. Dimensioning of diameters:
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34. Arrangement of Dimensions
7. Dimensioning of chords, arcs and angles:
8. Dimensioning of Radius:
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35. Arrangement of Dimensions
9. Dimensioning chamfers:
10. Dimensioning countersunks:
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36. Arrangement of Dimensions
11. Dimensioning Screw Thread:
12. DimensioningTaper Future:
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37. Notes in Dimensions
 Notes should always be written horizontally in capital
letters and begin above the leader line and may end
below also.
 Further, notes should be brief and clear and the wording
should be standard in form.
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40. BIS–SP 46
 BIS is the National Standards body formed by the
government of India on 1 April 1987, replacing ISI existing
earlier.
 The objective of BIS is to develop the industries and
commercial growth of the country by developing globally
acceptable standard for product.
 It works in association with other standard-developing
organization worldwide, in particular with the ISO.
 BIS has recommended & published various standards for
technical drawings.
 These standards are available in the form of IS code and
Special Publication 46: 2003.
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41. BIS–SP 46
 These standards are available in the form of IS code and
Special Publication 46: 2003.
 In short,
 The standard which is for “Engineering
Drawing Practice For Schools & Colleges”.
 And used in the educational institution for
engineering drawing or graphics.
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50. 1
2
3
4
5
6
7
8
9
10
BA
D
C
1
2
3
4
5
6
7
8
9
10
Steps:
1. Draw both axes as perpendicular bisectors
of each other & name their ends as shown.
2. Taking their intersecting point as a center,
draw two concentric circles considering both
as respective diameters.
3. Divide both circles in 12 equal parts &
name as shown.
4. From all points of outer circle draw vertical
lines downwards and upwards respectively.
5.From all points of inner circle draw
horizontal lines to intersect those vertical
lines.
6. Mark all intersecting points properly as
those are the points on ellipse.
7. Join all these points along with the ends of
both axes in smooth possible curve. It is
required ellipse.
Problem 1 :-
Draw ellipse by concentric circle method.
Take major axis 100 mm and minor axis 70 mm long.
ELLIPSE
BY CONCENTRIC CIRCLE METHOD
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