Sectional view

Explanation on the Concept of Sectional View

1. Sectional View By Ahmed Shah

2. What is a “Section View” ? A section view is a view used on a drawing to show an area or hidden part of an object by cutting away or removing some of that object. The cut line is called a “cutting plane” and can be done in several ways.

3. Purpose of Sectional View Clarify the views by reducing or eliminating the hidden lines, revealing the cross-sectional shape and describing the material Facilitate the dimensioning.

4. Purpose of Sectional View

5. Cutting Plane Cutting plane is an imaginary plane that cuts through the object A section view is obtained by viewing the object after removed the cover up part in the direction normal to the cutting plane. Location and direction of a cutting plane depend on a hidden feature that is needed to be revealed.

6. Sectional Lining Sectional lines or cross-hatched lines are added to a section view to indicate surface that are cut by the cutting plane.

7. Sectional Lining The section lines are different for each type of material. Practically, the cast iron symbol is used most often for any material.

8. Section Lining 45 O angle lines should be used. The distance between lines should be 1/8”. All lines should be uniformly spaced. Lines should never be parallel or perpendicular to the object lines. If the outline of the object has 45 O lines, 30 O or 60 O lines should be used. Assemblies with several parts should be lined with varying angle section lines.

9. Types of Sectional Views Full section Offset section Half section Broken-out section Revolved section (aligned section) Removed section (detail section)

10. Conventional Practices Hidden Lines are omitted within the sectional lined area.

11. Full Sectional View Full Sectional view is made by passing the straight cutting plane completely through the part.

12. Offset Sectional View Offset sectional view is made by passing the bending cutting plane completely through the part. The edge view of the cutting plane are omitted.

13. Half Sectional View A half section view is made by passing the cutting plane halfway through an object and remove a quarter of it. The line that separates the different Views may be a centerline or a visible line.

14. Broken Out Section Broken out section view is made by passing the cutting plane normal to the viewing direction and removing the portion of an object in front of it. The sectioned and unsectioned portions are separated by a break line. Break line are drawn freehand with a thin continuous line, the cutting plane line is not necessary.

15. Revolved section A section view is made by revolving the cross-section view 90° about a cutting plane line and drawn on the orthographic view. Revolved sections show cross sectional features of a part. No need for additional orthographic views. This section is especially helpful when a cross-section varies.

16. Removed Section View Removed section is created with the same concept as a revolved section. But the cross-section view is shown outside the view. Used where space is not enough for revolved sectional view.

17. Comparison Between Revolved and Removed

18. Section view of rib, web, spoke and lug The section lines on the section view of Rib, Web and Lug, is omitted if the cutting plane is passed flatwise through. And for spoke is omitted if the cutting plane is passed longwise through.

19. Sectional View of RIB Normal Multiview drawing Normal section view Section view drawing with convention

20. Sectional View of WEB Normal multiview drawing Normal section view Section view drawing with convention

21. Sectional View of SPOKE Misleading impression

22. Sectional View of LUG

23. Aligned Section Aligned section is a section view that is drawn by imaginary rotating the object’s features appeared in a principal view about symmetry axis

24. Aligned Section of Hole Gives the impression that this holes are at unsymmetrical position.

25. Aligned Section of Rib

26. Aligned Section of L ug

27. Conventional Break For long objects that needs to be drawn in a small scale to fit them on the paper, it is recommended to remove its long portion (which contains no important information) and draw the break lines at the broken ends.

28. STANDARD BREAK LINES Rectangular cross section Wood Metal Cylindrical cross section Tubular cross section

29. Thankyou !!!! Any Questions ???