2. Engineering means “Applied science”
Graphics means “drawings”
“Language of Engineers”
It is a way for communicating Engineer’s ideas, designs and
thoughts to others.
The communication of ideas through the graphical language.
It’s helps to reduce the time, increase the accuracy of the
object to be manufacture.
3. Freehand drawing
The lines are sketched without using instruments other
than pencils and erasers.
Example
4. Instrument drawing
Instruments are used to draw straight lines, circles, and
curves concisely and accurately. Thus, the drawings are usually
made to scale.
Example
5. ISO International Standards Organization
Standard Code
ANSI American National Standard InstituteUSA
JIS Japanese Industrial StandardJapan
BS British StandardUK
AS Australian StandardAustralia
Deutsches Institut für NormungDINGermany
Country Code Full name
India BIS Bureau of Indian Standards
6. Drawing Sheet
Trimmed paper of
a size A0 ~ A4.
Standard sheet size
(JIS)
A4 210 x 297
A3 297 x 420
A2 420 x 594
A1 594 x 841
A0 841 x 1189
A4
A3
A2
A1
A0(Dimensions in millimeters)
7. Drawing Scales
Scale is the ratio of the linear dimension of an element of an
object shown in the drawing to the real linear dimension of the
same element of the object.
Size in drawing Actual size
Length, size
:
8. Drawing Scales
Designation of a scale consists of the word “SCALE”
followed by the indication of its ratio, as follow
SCALE 1:1 for full size
SCALE X:1 for enlargement scales (X > 1)
SCALE 1:X for reduction scales (X > 1)
Dimension numbers shown in the drawing are correspond
to “true size” of the object and they are independent of
the scale used in creating that drawing.
9. Visible lines represent features that can be seen in the
current view
Meaning of Lines
Hidden lines represent features that can not be seen in
the current view
Center line represents symmetry, path of motion, centers
of circles, axis of axisymmetrical parts
Dimension and Extension lines indicate the sizes and
location of features on a drawing
11. Text on engineering drawing is used :
To communicate nongraphic information.
As a substitute for graphic information, in those instance
where text can communicate the needed information more
clearly and quickly.
Uniformity - size
- line thickness
Legibility - shape
- space between letters and words
Thus, it must be written with
14. It’s a rectangular
wooden board 22 mm
of thick and size is
650*470 mm
15. Drawing board must be placed on the table with working edge
always to be at the left side.
Working edge
16. It’s a combined form of
T-square ,Set square
Protractors and scale. One
end of the drafter is
Clamped at the left top
end.
17. High-quality drawing pencils should be used in technical drawing,
never ordinary writing pencils.
HB(soft grade) – used for lettering, freehand sketching
H ( medium grade ) - used for visible outlines, edges
2H(hard grade) - used for dimension line, hidden line
20. Standard form of arrangement
Important particulars are included
Facilitate quick reading of important particulars – quick
references are located easily – drawings are prepared at
various locations and shared
21. space left all around in between the trimmed edges of the sheet
a minimum of 10 mm
23. Dimensions of large objects must be reduced to accommodate
on standard size drawing sheet.
This reduction creates a scale of that reduction ratio.
This ratio is called reducing scale
Full scale 1:1
Reducing scale 1:2,1:5,1:10
Enlarging scale 2:1,5:1,10:1
24. Point : A point is not a thing, but a place. We indicate the
position.
Line joining of two point but no breath and think
Polygon :it’s a plane figure more than 4 straight lines
Depending on the number of sides the regular polygon are
classified as
1) Rectangle, 2) Pentagon, 3) Hexagon, 4) Heptagon,
5) Octagon, 6) Nonagon.
3-1024 sides is name as polygon.
25. Vertical plane –when the observer is viewing it from the
front.
It shows only two dimension length and height.
Horizontal plane – when the observer is viewing it from top.
It shows only breath.
26.
27.
28.
29. It’s in first quadrant.
Top view comes below to the front view
30. It’s in third quadrant
Top view comes above the front view
