Bruce Mayer, PE Registered Electrical & Mechanical Engineer BMayer@ChabotCollege

[email protected] • ENGR-22_Lec-11_Section-Views-1.ppt1

Bruce Mayer, PE Engineering 22 – Engineering Design Graphics

Bruce Mayer, PERegistered Electrical & Mechanical Engineer

[email protected]

Engineering 22

SectionSectionViews-1Views-1



Learning GoalsLearning Goals

Properly Create Section (Cut-Away) Views to Show Internal Features Of Objects That Are Not Easily Understood In Standard Orthographic Projection View Drawings



Learning Goals Learning Goals contcont

Use and/or Apply• How & Where to Construct the Cutting

Plane Line

• Section Lines (a.k.a. “Hatch Lines”)

• Several Types of Section Drawings



Section ViewsSection Views Definition: An Orthographic Technical

Drawing That Reveals Details About INTERNAL Features By Displaying The Part As If Cut By An Imaginary Plane



Section Views Section Views contcont

Usefulness: • Makes the Drawing More Understandable,

Especially The Internal Details Of The Part

• Since The Sectioned Drawing Shows Internal Features There Is Generally NO NEED To Show HIDDEN Lines

• Especially helpful for – Complex Part Fabrication

– Assembly Drawings



Some Assembly DrawingsSome Assembly Drawings



The Cutting PlaneThe Cutting Plane

An imaginary plane that defines where the object is cut

Shown in drawing ADJACENT to the Sectioned View

Drawn with the PHANTOM or HIDDEN line type

Arrows at the end of the cutting plane line indicate the direction of view for the sectioned drawing.



The Cutting Plane cont.The Cutting Plane cont.

The arrows point TOWARD the part of the object that is VISIBLE in the sectioned view

A sectioned drawing follows the general rules of any view in an OrthoGraphic MULTIVIEW drawing



Multiple Cutting PlanesMultiple Cutting Planes Cutting planes may be labeled

at their endpoints if multiple cutting plane lines are used

When using multiple cutting planes each sectioned drawing is drawn as if the other cutting plane lines do not exist

The cutting plane line takes precedence over center lines

Cutting planes may by omitted when their location is obvious



Section View PlacementSection View Placement

The Section View is Placed “Opposite” to the Direction of the Cutting Plane Arrows• The Arrows are Rotated INTO the Paper to

Reveal the Section



Cross Hatch LinesCross Hatch Lines Cross-Hatch Lines are drawn

where the object passes through the cutting plane

If a saw were used to cut the part then Hatch lines represent the cutting (tool) marks left by the saw blade

Different materials may be represented by the use of different Hatch line types• The general Hatch

line type which may be used for any material is the line type for IRON



Hatch Line ConventionsHatch Line Conventions Hatch lines should NOT be PARALLEL or

PERPENDICULAR to object lines Hatch lines are generally drawn at 45° unless this

conflicts with other rules Hatch lines should be oriented at different angles for

separate parts Occasionally Hatch lines are only drawn on the

perimeter of large areas (not an issue with CAD) Hatch lines are not used for thin parts rather they are

filled in solid (Do not use closely spaced Hatch lines)



Section Line Conventions cont.Section Line Conventions cont. Cutting Plane Lines Take

Precedence over Center Lines

Hatch Line Density• Should Clearly Identify the

Cut Material

• Not be Too Dense As This Tends to Obscure Object lines



Sketch DemoSketch Demo Using the White Board, Let’s

Make Some Cross Section Drawings

A

B

C



Prob-A SolutionProb-A Solution



Prob-B SolutionProb-B Solution



Prob-C SolutionProb-C Solution



All Done for TodayAll Done for Today

Blue PrintCrossSec

Circa 1862



Bruce Mayer, PELicensed Electrical & Mechanical Engineer

[email protected]

Engr/Math/Physics 25

AppendiAppendixx

6972 23 xxxxf



Prob-A Solution - 1 Prob-A Solution - 1 Grid it



Prob-A Solution - 2 Prob-A Solution - 2 Connect

Dots to Block In OutLine




Dots to Reveal Sliced Edges



Prob-A Solution - 4 Prob-A Solution - 4 Construct

View of Rounded-End Slot• Circle

• Trim

• Pedit (turn ½-circles into Plines)

• Pline




the Dots to Reveal Sliced Areas

Hatch the Sliced Areas



Prob-A Solution - 6 Prob-A Solution - 6 Strip Out

Constr Lines, and Add Center Marks & Lines to Show Completed Cross-Section

Bruce Mayer, PE Registered Electrical & Mechanical Engineer BMayer@ChabotCollege

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