here introduction to computer aided design like types of projection. views ,orthographic views then types of lines,and general information regarding drafting standard and various symbols about GD & T content and basic information of threads.

1. Computer Aided Design
(CAD)
Engineering Drawing Standards - BS308

2. Orthographic Projection

3. Orthographic Projection

4. Orthographic Projection

5. SOME TECHNICAL TERMS (page 1)
Flange
Keyway
Keyway
Key
Taper
Shaft
Shoulder
Bush Web Bore Boss Collar Spoke Rim Hub
Pulley
Rib
Bracket
base
Fillet
Table
Slot
Spotface
Counterbore
Lug
Countersink
Dowel
Blind hole
Tee slot
Chamfer
Spigot
Recess

6. SOME TECHNICAL TERMS (page 1)
CAN YOU DETERMINE THE PROJECTION SYSTEM
USED? (first or third angle?)
CAN YOU IDENTIFY THE TYPES OF HOLES ABOVE?

7. Projection Symbol – How to Draw

8. COMMON LINE TYPES (page 5)
 1. Continuous Thick (0.5mm) TYPE A
 2. Continuous Thin (0.25mm) TYPE B
 3. Dashed Thin (0.25mm) TYPE E
 4. Chain Thin (0.25mm) TYPE F

9. LINETYPES
 Hidden
 Center
 Hatch
 Outlines
 Text
 Dimension
Lines
 Leader
Lines

10. Leader Lines
 To show where dimensions or notes apply.
 Always end in arrowheads or dots.
 Arrowheads touch and stop on a line
 Dots should be within the outline of the object.
 Long or intersecting leader lines should not
be used.

11. General Points on Drafting
 Arrows:
 Triangular and Solid
 Length = 3 x width
 Arrows on Dimensions -> 3-5mm Long
 Arrows showing direction of view -> 7-10mm Long
 Text Height = Not less than 3mm.
 Underlining of text is not recommended.
 Notes of a general character to be grouped
together.

12. General Points on Drafting

13. Commonly Accepted Symbols
and Abbreviations
 AF
 ASSY
 CRS
 CL
 CHAM
 CH HD
 CSK
 CSK HD
 CBORE
 CYL
 DIA
 DRG
 EQUI SP
 EXT
 FIG.
 HEX
 HYD
 INSUL
 INT
 LH
 LG
 MATL
 MAX
 MIN

14. Commonly Accepted Symbols
and Abbreviations
 NO.
 O/D
 PATT NO.
 PCD
 RAD
 R
 REQD
 RH
 RD HD
 SCR
 SH
 SK
 SPEC
 SR
 SFACE
 SQ
 STD
 THD
 TYP
 UCUT
 VOL
 WT

15. SCREW THREAD - TERMS

16. SCREW THREAD - TYPES

17. SCREW THREAD - External
NOTE:
Inner lines are Type
2 Lines (Continous
Thin Lines)

18. SCREW THREAD - Internal
NOTE:
Inner lines are Type
2 Lines (Continous
Thin Lines)

19. SCREW THREAD - Internal

20. SECTIONS AND SECTIONAL VIEWS
(page 12 BS308)
 Hatching is Drawn with Type B (Continuous
Thin) Lines, equally spaced at 45º.
 Preferably not less than 4mm Apart
 With very small parts, never less than 1mm
 On adjacent parts, alternate the direction
of Hatching.
 Correct Section Line – Type F (Chain Thin)

21. SECTIONS AND SECTIONAL VIEWS

22. SECTIONS AND SECTIONAL VIEWS

23. SECTIONS AND SECTIONAL VIEWS

24. SECTIONS AND SECTIONAL VIEWS

25. SECTIONS AND SECTIONAL VIEWS
(page 15 BS308)
 PARTS NOT NORMALLY SECTIONED WHEN
THE CUTTING PLANE PASSES
LONGITUDINALLY THROUGH:
FASTNERS (bolts, nuts) SHAFTS, RIBS,
WEBS, SPOKES of WHEELS etc.

26. SECTIONS AND SECTIONAL VIEWS
(page 15 BS308)
FASTNERS
AND SHAFT
NOT
SECTIONED
WEB NOT
SECTONED

28. OFFSET SECTION
SECTION IN MORE THAN 1 PLANE

29. EXTRA RESOURCE INFORMATION
 DeGarmo, E. P., et al., Materials and
Processes in Manufacturing, 8th Ed.,
Maxwell Macmillan, 1997