Sectional views reveal hidden details in a mechanical drawing. These views assume that a cutting plane has removed portions of the object represented by the drawing, displaying the appropriate section of the interior. Sectional views are used in engineering and architectural drawings. They help civil engineers, architects, and airplane designers communicate their ideas to their peers. The different types of sectional views assist them in this process.
If the imaginary cutting plane passes through the entire object, splitting the drawn object in two with the interior of the object revealed, this is called a "full section." A full section is the most widely-used sectional view.
In this view, the cutting plane is assumed to bend at a right angle and cuts through only half of the represented object, not the full length. When the quarter of the object that was cut is removed, the remainder is called a "half section." A half section view is effective only on symmetrical objects, and its main purpose is to show an object's internal and external construction in the same drawing.
When specific features of an object that need highlighting are not located on the straight line of the cutting plane, an irregular-shaped cutting plane is imagined cutting the object, revealing the desired components. This is called an "offset view," and is effective on complex objects. The bends in the imaginary cutting pane are always 90 degrees.
A "revolving view" is effective for elongated objects or the elongated section of an object. In this view, the cross-sectional shape of ribs, spokes, and other projections of the object are featured. The cutting plane cuts the object at an angle, but the drawing is rotated for a better view by the observer.
When only a small part of the object needs viewing, the cutting plane is not used. An irregular cut line removes a section of the object at the desired depth, leaving a "broken view." A broken view is helpful when only specific interior details in a certain part of the object need featuring.
