Sectional Views (2024)

FAQs

Sectional Views? ›

A sectional view represents the part of an object remaining after a portion is assumed to have been cut and removed. The exposed cut surface is then indicated by section lines. Hidden features behind the cutting plane are omitted, unless required for dimensioning or for definition of the part.

Rules of Sectioning

Rule 1: A section lined area is always completely bounded by a visible outline. Rule 2: The section lines in all areas should be parallel. Section lines shown in opposite directions indicate a different part. Rule 3: All the visible edges behind the cutting plane should be shown.

A section view is an orthographic projection view drawn to reveal internal or hidden features in an object. Section views are used to supplement standard orthographic view drawings in order to completely describe an object.

Britannica Dictionary definition of CROSS SECTION. 1. : a view or drawing that shows what the inside of something looks like after a cut has been made across it.

A half-section is a view of an object showing one-half of the view in section. Half Section. • Symmetrical parts can be shown in half sections.

When sketching an object or part that requires a sectional view, they are drawn by eye at an angle of approximately 45 degrees, and are spaced about 1/8” apart. Since they are used to set off a section, they must be drawn with care. It is best to use the symbol for the material being shown as a section on a sketch.

 To document the design and manufacture of single parts that is manufactured as one piece.  To document how multiple parts are to be assembled or built.  To aid in visualizing the internal workings of a design.

Types of section views. Depending on the shape of the cutting plane and the details shown, a section view may be classified as a full, half, offset, aligned, or broken-out section.

A half section view is a variation of a full section view that shows only one half of the cross-section of the object. It is usually used for symmetrical objects or objects with repetitive features.

Unlike a cross-section, which shows all of the part of the object covered by the cutting plane line and its details, a section shows only a part of the surface located on the cutting plane of that object.

Do sectional views allow you to see the outside of an object? ›

A half section has the advantage of showing both inside and outside configurations. It is frequently used for symmetrical objects. Hidden lines are usually not shown on the un-sectioned half unless they are needed for clearness or for dimensioning purposes.

While a typical section is a cross sectional view of a roadway or other continuous element looking along its centerline, the profile is a cross section view perpendicular to the path of travel.

Full Section. In a full section, the cutting plane line passes fully through the part. Normally a view is replaced with the full section view. The section-lined areas are those portions that have been in actual contact with the cutting-plane.

This symbol indicates the projection method used in the drawing. When the large end of the cone in the section view is closest to the top view, this is known as first angle projection. Traditionally, the first angle projection symbol is drawn with the top view on the left and the side view on the right.

3rd Angle project is where the 3D object is seen to be in the 3rd quadrant. It is positioned below and behind the viewing planes, the planes are transparent, and each view is pulled onto the plane closest to it. The front plane of projection is seen to be between the observer and the object.

There are a number of different types of sectional views that can be drawn. A few of the more common ones are: full sections, half sections, broken sections, rotated or revolved sections, removed sections, offset sections, and assembly sections.

Offsets or bends created by the cutting plane are not shown on the section view.

Full Section: The object is cut through entirely. Half Section: Only half the object is sectioned. Ideal for symmetrical objects. Broken Out Section: A part of the object is cut away to reveal features without a cutting plane line.

This is the most common section (called a full section) with the imaginary laser cutting a line across the entire construction, offering a view of a portion of the building with the rest of it put to one side. Half sections or views.