1. 2D Essentials
Instructor: Laura Gerold, PE
Catalog #10614113
Class # 22784, 24113, 24136, & 24138
Class Start: January 18, 2012
Class End: May 16, 2012

2. Reminders
• Optional extra credit is due today
• Final Project is due on May 9th.
• Final Exam is May 16th.

3. “Mid-term” Survey
• Take out a sheet of paper and answer the following
questions about me. You do not need to sign the paper.
Justin and Jacob, you can email me your responses.
1. I think it would help me if we did MORE:
2. The thing I like doing best/is most helpful is:
3. If there is one thing I could change about this course, it
would be:
4. If there is one thing I would want the instructor to know it
would be:
5. In this class I thought we were going to:
6. One thing I hope we have time to cover is:
7. In the last half, the thing I'd like MOST to concentrate on is:
8. In the last half, the thing I'd like LEAST to concentrate on is:
9. OTHER COMMENTS:

4. Project Tips
• Use a light lead and a fine point for your first drawing of the
object. Erase construction lines and then darken in the final
lines using a darker lead.
• Project descriptions to show all six orthographic views . . . I’m
making the executive decision to change it to necessary views.
• Unsure of necessary views? Talk to me after class today or
before class next week about your project.

5. Chapter 7 – Section
Views

6. When is it appropriate to show
hidden lines in section view?
• Hidden lines should NOT be shown when they will “clutter”
the view
• Hidden lines can be shown when they are necessary to show
detail of the object

7. Can Section Views be located
off of the center?
• Yes!!
• Section Views should be shown when there is a “change” in an
object.
• If an object is uniform, show it the section view in the center
of the object.
• If there are changes in the object, show additional section
views at additional locations.
• Remember – the point of section views is to be able to build
an item by giving all the necessary information.

8. What is the difference between a Section
View Line and a Removed View Line?
• A Removed view line is shown outside of the drawn
object, while the section view line is inside the object.
Removed View Using
Viewing-Plane Line Section View Using
Viewing-Plane Line

9. New Groups!!
• We are going to mix up the groups in class today.
• Make a new group of 2 to 3 people composed of one person
from each row.

10. Group Project - Section View
Locations
• With your new group, locate a complex item in the classroom
or on a brief trip outside of the classroom that would take
more than one section view to describe.
• Do a quick sketch of the item (with section views).
• Describe what you found to the group.

11. Line Precedence
• What take precedence? A cutting-plane line or a centerline?

12. Line Precedence
• What take precedence? The cutting plane line!
• When a cutting plane line would obscure important
details, just end the line outside the view and show the arrows
• Make sure to leave a small, but visible gap.

13. SECTION-LINING TECHNIQUE
• Uniformly spaced by an interval of about 2.5 mm
• Not too close together
• Uniformly thin, not varying in thickness
• Distinctly thinner than visible lines
• Neither running beyond nor stopping short of visible
outlines

14. Section-Lining Symbols
Section-lining symbols (hatch) may be used to indicate specific materials.
These symbols represent general material types only, such as cast
iron, brass, and steel.
Symbols for Section Lining

15. Hatch Pop Quiz
• You are a producer of kids’ rubber balls for use in gym class.
You are given a solid rubber ball and told to draw a section
view to use to create the ball on the line.
• Draw a quick sketch of the section view with the correct hatch
pattern.

16. Hatch Pop Quiz
• You are putting a galvanized steel pipe into your factory. Your
boss needs a section view of the pipe.
• Sketch a quick section view showing the proper hatch.

17. Hatch Pop Quiz
• Your factory makes the best cast iron skillets in America. You
are given a cast iron skillet and told to draw a section view for
use in production of the skillet.
• Draw a quick section view using the correct hatch.

18. Hatch Pop Quiz
• Copper piping is being put into your workplace to replace old
drinking water piping.
• Draw a quick section view sketch of a copper pipe

19. Hatch Pop Quiz
• Your company produces all things zinc. A popular item is a
zinc nut.
• Draw a quick section view showing the proper hatching.

20. Hatch Pop Quiz
• Magnesium is the third most commonly used structural metal
after iron and aluminum. It is strong and light.
• Your company makes Magnesium die cast components.
Sketch a quick section view using the appropriate section line
hatch.

21. HALF SECTIONS
• Symmetrical objects can be shown
effectively using a special type of section
view called a half section.
• A half section exposes the interior of half
of the object and the exterior of the other
half.
• This is done by removing one quarter of the
object.

22. HALF SECTIONS
• In general
• Omit hidden lines from both halves when possible
• Use a centerline to divide the section and non-sectioned half
• Half Sections are most useful in showing an assembly where it
is necessary to show both internal and external construction
in one drawing view.
• In general, half sections are not widely used.
Cutting plane
Half section

23. Half Section Drawing Example
• Now I’m going to draw you a beautiful quarter section view of
a candy bar . . .

24. Group Project – Half Sections
• Pick a candy bar and use your cutting plane (plastic knife) to
cut a quarter section out of the bar.
• Now draw a top view and a half section view of the candy bar.
• Show and Label the cutting plane
• Use a hatch of your own chose to describe the filling

25. BROKEN OUT SECTIONS
It often happens that
only a partial section of
a view is needed to
expose interior shapes.
Such a section, limited
by a break line, is
called a broken out
section.

26. Broken Out Section Drawing
Example
• Now I’m going to draw you a beautiful broken out section
view of a candy bar . . .

27. Group Project – Broken Out
Sections
• Pick a candy bar and use your cutting plane (plastic knife) to
cut a broken out section out of the bar.
• Now draw a top view and a broken out section view of the
candy bar.
• Show and Label the cutting plane
• Use a hatch of your own chose to describe the filling

28. REVOLVED SECTIONS
The shape of the cross section
of a bar, arm, spoke, or other
elongated object can be shown
in the longitudinal view by using
a revolved section.
90°
To create a revolved section, first imagine a cutting
plane perpendicular to the centerline or axis of the
object. Next, revolve the plane 90° about a
centerline at right angles to the axis.

29. Revolved Section Drawing
Example
• Now I’m going to draw you a beautiful revolved section view
of a cylinder. . .

30. Group Project – Revolved
Sections
• Use a cylinder (or a twix) and visualize a revolved section view
• Now draw a top view and a revolved section view of the candy
bar.
• Show and Label the cutting plane
• Use a hatch of your own chose to describe the filling

31. REMOVED SECTIONS
A removed section is
one that is not in direct
projection from the view
containing the cutting
plane — that is, it is not
positioned in agreement
with the standard
arrangement of views.

32. REMOVED SECTIONS
• If you must rotate the view, use a rotation arrow to note the
angle the view was rotated.
• Removed views should be labeled such as Section A-A or B-B
to correspond to the cutting plane line
• Removed views should be arranged in alphabetical order from
left to right on the sheet.
• Do not use letters, I, O, and Q for Section labeling as they can
easily be confused with numbers 1 and 0.

33. REMOVED SECTIONS
• Removed views are also known as partial sections
• They are often drawn at an enlarged scale (like a detail)
• If you show the section at an enlarged scale, make sure to
note the new scale under the detail
• Try to keep removed views on the same sheet as the regular
views. If it needs to be on a separate sheet, make a note such
as SECTION B-B ON SHEET 4, ZONE A3

34. Removed Section Drawing
Example
• Now I’m going to draw you a beautiful removed section view
of a candy bar . . .

35. Group Project – Removed
Sections
• Pick a candy bar and use your cutting plane (plastic knife) to
cut a full section out of the bar.
• Now draw a top view and a removed section view of the
candy bar.
• Show and Label the cutting plane
• Use a hatch of your own chose to describe the filling

36. OFFSET SECTIONS
In sectioning complex objects, it is often desirable to show features that do not lie in a
straight line by “offsetting” or bending the cutting plane. These are called offset sections.
Note the offset cutting plane line
Note the hidden lines in the section view make it so
Another view is not needed.

37. Offset Section Drawing
Example
• Now I’m going to draw you a beautiful offset section view of a
candy bar . . .

38. Group Project – Offset Sections
• Pick a candy bar and use your cutting plane (plastic knife) to
cut an offset section out of the bar.
• Now draw a top view and an offset section view of the candy
bar.
• Show and Label the cutting plane
• Use a hatch of your own chose to describe the filling

39. RIBS IN SECTION
To avoid giving a false impression of thickness and
solidity, ribs, webs, gear teeth, and other similar flat features are not
hatched with section lining even though the cutting plane slices them.
Thin features are not hatched
even though the cutting plane
passes lengthwise through
them.

40. ALIGNED SECTIONS
When parts with angled elements are sectioned, the cutting plane may be
bent to pass through those features. The plane and features are then
imagined to be revolved into the original plane.
The angle of revolution should
always be less than 90° for
an aligned section.
Aligned Section

41. Group Project – Aligned
Sections
• Each group will be assigned a graphic: 7.37, 7.38, 7.39, 7.40.
• Talk through the illustration with you group and make sure
you understand what the graphic is showing you
• How would you teach this to the class? Can you show an
example or can you talk through the explanation?
• Show the graphic to the class and teach your classmates about
it.

42. PARTIAL VIEWS
If space is limited on the paper or to save time, partial views may be used
with sectioning.
Another method of drawing a partial view is to break out much of the
circular view, retaining only those features that are needed for minimum
representation.

43. INTERSECTIONS IN SECTIONS
Whenever an intersection is small or unimportant in a section, it is standard
practice to disregard the true projection of the figure of intersection.
Larger intersections
may be projected
Note that the larger hole K
is the same diameter as the
vertical hole. In such cases
the curves of intersection
(ellipses) appear as straight
lines.

44. CONVENTIONAL BREAKS
AND SECTIONS
Conventional breaks are used to shorten the view of an object that is too
long to show clearly at one scale on the drawing sheet.

45. ASSEMBLY SECTIONS
Section views are often used to create assembly drawings.
Notice that the hatching on different parts has different
hatch patterns or hatch at different angles. When used on
the same part, the hatching is always at the same angle
to help you recognize the parts easily.

46. How to draw a section view of
a coffee cup . . .
• Section View of a Coffee Cup

47. Section Views Visualization
Exercise
• http://www.wisc-
online.com/objects/ViewObject.aspx?ID=ENG19804

48. Group Project
• Each group take a type of section view
• Full Section
• Half Section
• Broken-Out Section
• Removed Section
• Revolved Section
• Aligned Section
• Offset Section
• Determine a way good way to teach this type of section view
to the rest of the class
• Do a brief mini-lesson in front of the class

49. What’s Next?
• Chapter 8 – Auxiliary Views

50. Questions?
• On one of your sketches, answer the following
two questions:
• What was the most useful thing that you
learned today?
• What do you still have questions about?

51. Homework
Read Chapter 8
Chapter 7 Review Questions: 2, 3, 5, 6, 7
Chapter 7 Sectioning Exercises: 7.1