Sectional Drawing Views Sections, or sectional views, are used

to describe the interior portions of an object that are otherwise difficult to visualize

Section views are used to get rid of the confusing hidden lines. They are a way to, in our imagination, cut through an object and create an orthographic view inside the object.  It is as if the object were cut in two. Normally the sectional view takes the place of a regular view.

Section Lines Usually drawn equally spaced and at a

45°angle ( alternative angles: 30°,60°)

Larger parts have larger spacing May not be drawn parallel or

perpendicular to any line of the object Never draw horizontal or vertical Draw at opposite angles on adjacent

parts Use general section lines or coded

section lines

The material that is supposedly cut is "Hatched" with patterns.  The patterns often depict the actual material of the object. The most commonly used is the cast iron or general use.

Cutting Plane Line

A thick line that represents the edge view of a cutting plane through a part.

The cutting plane line is capped on the ends with arrowheads that show direction of sight of the sectional view.

The cutting plane line and related sections should be labeled with letters beginning with “A.”

Slicing a Part

Click here for the Slicing the Part Animation

Click here to the Cutting Plane Animation

Types of Sections

Full Sections Half Sections Offset Sections Aligned Sections Revolved Sections Removed Sections

The cutting plane extends straight through the object. Notice that the 45 ° sections are shown where the cutting plane cuts through the actual material of the object.

Full Sections

Click here for the Full Section Animation

Half Sections Half Section Views are used primarily on

symmetrically shaped objects. They cut through half of the object.

Click Here for the Half Section Animation

Offset Sections Offset Section Views are like full section views

except that the Cutting Plane bends to follow certain features inside the object.

Click Here for the Offset Section Animation

Revolved Sections Revolved Views are a shortcut way to show a section view that

shows the internal shape of an object without creating a completely separate section view.    The cutting plane passes through the object at the desired location and is revolved, in place, to show the section view. 

Click Here for the Revolved Animation

Removed Sections Type of section that is moved from its normal position

to a more convenient position on the drawing.

Aligned Sections Used when it is important to include details of a part by bending

the cutting plane. The cutting plane and the feature are imagined to be aligned or revolved before the section view is created. 

Click Here for the Aligned Animation

Conventional Breaks Conventional Breaks are a way of depicting a very long

object without showing the entire length.  It is often used for objects like solid shaft or a length of tubing.

Broken Out Sections Used when only a small part of a view needs to be

sectioned to show detail of construction.

Ribs and Webs

Rib and Web are thin, flat feature of an

object that acts as a structural support.

Spoke

Spoke is the rod radiating from the hub to the rim of a wheel. Spokes are not sectioned.

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Rim

Spoke

Spoke

Rim

HubHub