1. TA 101: Technical Arts 2015-16 II Dr. Prishati Raychowdhury
Department of Civil Engineering
IIT Kanpur
Office: FB 330; Phone: 6692

2. Lecture 11
Sectional Views

3. What is Sectioning?
Cutting an object

4. Need for sectioning A B C B C A AA BB CC

6. Need for sectioning

7. Need for sectioning

8. Sectional Views
A view of an object when it is ‘sectioned’ or ‘cut’ by an imaginary plane to reveal interior details of the object
Sectional view is usually (but, not always) parallel to one of the principal orthographic planes e.g. frontal, top, or profile
A sectional view must indicate which portions of the object are solid and which are spaces

9. Cutting Plane An imaginary plane that cuts the object
Generally indicated in an adjacent view with a line and two arrows
Generally named by letters : AA, BB etc A

10. Full Section Cutting plane passes completely through the object
One cutting plane, it need not be straight

11. Half section
Half sections are used for symmetrical objects in which one half is shown in section and other half in regular exterior
Advantage: showing both interior and exterior in one view

12. Rotated/ Revolved Section
Cut section rotated by 90o

13. Auxiliary Section

14. Drawing Sectional Views
Visible edges shown in Main part hatched with 45o lines (2H)

15. Drawing Sectional Views
Different parts are hatched at 30o, 60o, etc

16. Material Specific Hatching

17. Parts NOT Hatched Spokes Ribs
Standard components like nuts, bolts, shafts, pins etc

18. Parts NOT Hatched
Spokes are not hatched: to distinguish between Fig A and Fig B
Solid wheel
Wheel with spokes

19. Parts NOT Hatched
Ribs not sectioned: otherwise they give the impression of a solid part

20. Parts NOT Hatched
Ribs not sectioned in longitudinal section (along axis)

21. Parts NOT Hatched
Ribs are hatched in transverse section (although this section is rarely taken)

23. Hidden Lines
Hidden lines are not shown in sectional views (unless absolutely necessary)
Section B is preferred over A

24. Important Note
Sections are to be used only if some new information is revealed
Use half section only if full section will not reveal any new information
Sections should be hatched appropriately
NO HIDDEN lines are to be shown in sections

25. Example: sectional view

26. Assembly Drawings
A system (machine/house/computer, etc.) consists of many parts joined together in relation to each other
A total drawing will be made up of Assembly, sub-assembly and part drawings
A drawing may be viewed for a particular purpose: manufacturer, customer, information

27. Sectional Assemblies
Single lug chain

28. Sequence of manufacture
Step 1

29. Sequence of manufacture
Step 2

30. Sequence of manufacture
Step 3

31. Sequence of manufacture
Step 4

32. Concept
Top view

33. Concept
Importance of Sectional view
Know the fitting among the parts

34. Concept Importance of Sectional view
Understand the alignment among the parts

35. Rules for Assembly Drawings
Understand the function as a whole
Understand the function of each part
Decide the number of views required
Estimate the size of each view
Put the overall major dimensions only
Don’t show hidden lines if it can be avoided
Label parts with leader lines and numbers in circles
Sections only if required

36. Example
Bell Roller Support

37. Example
Bell Roller Support…

38. Example
Bell Roller Support…

39. Copper Rotor Motor
Source:

40. Thank you..
Next Day: AutoCAD