Sectional Views

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Sectional Views

• Engineering Graphics Design

By John Kirby
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Sectional Views

• Cut into the drawing
• Reduce confusion of excessive hidden lines
• Hatch lines represent the interior mass
• Aid visualizing the internal workings of a drawing

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Alphabet of Lines
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Crosshatching
Crosshatching patterns represent the various
metals and materials used in Engineering Graphics
Design.
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Full Sections

• Cuts the drawing completely apart
• Cuts generally horizontal or vertical from one
  end to the other
• Cuts often pass through the center of the drawing

Acceptable styles for cutting plane lines
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Full Section
Part Outline heavy weight line
Cutting Plane Line
Crosshatching
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Half Sections

• A half section is one half of a full section
• ¼ of the object is cut
• Two cutting plane lines at right angles
• ½ of the view is represented by the cut
• Used when drawing symmetrical objects

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Half Sections of 4 Step Pulley
Part Outline heavy weight line
Half Section cutting plane line drawn at right
angle
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Offset Sections

• Cutting plane lines are shifted to include
  missing details
• Cutting plane lines only view areas along the
  cutting plane line
• Cutting plane lines are offset to include more
  details

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Offset Section
Cutting Plane line does not include holes behind
the line.
Offset Cutting Plane line does includes holes
along the line.
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Break Out Sections

• Removes a defined area of material
• Exposes obscured parts or features in an existing
  drawing view
• View must be associated to a sketch that contains
  the profile defining the break out boundary

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Break Out View of Part
Break Out View exposes inside of part with
counter bore with threaded hole
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Break Out View of Assembly Drawing
A Break Out View can also be utilized on assembly
drawings to view inside of assemblies.
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Detail View

• Represents a specified portion of a view
• Assigning any scale to the view
• Used a zoom to enlarge areas better represented
  by enlarging for clarity

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Detail View of Box Assembly
Box Assembly is drawn ½ scale where the detail
view is drawn full scale. Dimensions included on
Detail B.
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Detail View of a Break Out View
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Broken View

• Used when the component view exceeds the length
  of the drawing
• Used when scaling the component view to fit the
  drawing makes the component view prohibitively
  small
• Used view contains large areas of nondescript
  geometry

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Broken View of an Assembly Drawing
Break Lines inserted to reduce the actual length
of the assembly. Dimension line above also
denotes the break.
Can you identify and label the other three types
of lines used in the drawing?
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Auxiliary View

• Helper view that aligns with the view from which
  it is projected
• Are used when true orthographic projections would
  distort the true shape of the object
• Are aligned with the projection lines of the
  auxiliary view

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Three View Projection without Auxiliary View
Representation
The top and right side views do not truly
represent the actual shape of the part.
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Auxiliary View with Detail Section
Projected View aligns with Detail B to insure a
true shape of the part.
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Auxiliary View with Projected Details for Clarity
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Exceptions for Clarity
Offset Section
Full Section
Which view best represents the pulley?
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Can you identify the two types of sections used
below?
A half section
A break out section
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What type of drawing is illustrated below?
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What type of section view is represented below?
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What type of section is represented below? When
is this type of view used?
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What type of view is represented below? When is
this technique applied?
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There are two drawing techniques mentioned
earlier in the drawing below Identify each and
explain.
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Identify the type of cutting plane below Why
was it used in this drawing?