Section Views

Section Views are used to show Hidden Features

Imaginary Cutting Plane and Line of Sight

Hidden Lines become Visible Lines in Section Views

Half Section The imaginary cutting plane cuts through a quarter of the flange resulting in a half section. Notice the cutting plane line in the top view and the direction of one arrow. Also notice that the right side of the half section view is the same as the orthographic view without hidden lines being shown.

Broken-Out Section Broken-Out Sections are used to show the interior details of a specific feature of the object. Notice that the cutting plane is not shown in the top view. Typically hidden lines are omitted from the Broken-Out Section View.

Revolved Sections Revolved Sections can be shown using the two methods shown in figures A and B. Method B is typically selected over Method A. Notice that the width of the revolved section is determined by the depth in the top view.

Removed Sections Removed Sections are actually Revolved Sections that are moved to another location on the drawing. Removed Sections are used when a part such as this connecting rod changes in cross-section from one point to another. This is not a great example of a Removed Section due to the fact that all of the Sections were taken where the cross-section remains relatively constant. Notice the convention of labeling the Sections A-A, B-B and C-C.

Offset Sections Offset Sections are used when there are several circular holes or slots that must be shown to fully depict the object. Notice that the cutting plane line turns at 90 to “pick up” all of the holes and slots. Notice that the imaginary cutting plane does not produce a visible line in the Offset Section view.

Aligned Sections Aligned Sections are used for symmetrical objects such as this flange which has holes drilled in it along a radial distance. The true projection as shown in Figure A does not accurately depict the object. The holes are aligned as shown in Figure B such that the flange and drilled holes are symmetrical.

Aligning Ribs Notice that the “True” projection does not accurately depict this flange and its drilled holes. Figure B shows the preferred right side orthographic view. Figure C is the aligned section view. Why are the ribs not hatched in the section view?

Omitting Section Lines on Webs Section lines or hatching patterns are omitted from section views of objects such as this wheel when the web is not continuous throughout the object. If the web was hatched it would be misleading to the reader indicating that the web was continuous. In this object it is obvious that the web is not continuous and therefore it should not be hatched.

Conventional Practices for Webs in Section Views Webs and other thin or support parts are not hatched. Hatching them would mislead the reader into thinking that the webs are not support parts. Notice that in Section A-A the web is hatched while in Section B-B it is not. Does this make sense to you?