Graphics: Orthographic Drawings and Section views

Orthographic Projection

A method of producing dimensioned working drawings (or blueprints) of 3D objects using a series of related 2D views to communicate the object's length, width, and depth.

Multiview Drawings

Another term for Orthographic Projections.

Principal Views (Six)

The six views used in orthographic projection

Three Main Views

For simple objects, the three main views are typically the Top, Front, and Right Side.

View Alignment (Vertical)

The Front and Top views are always in line vertically.

View Alignment (Horizontal)

The Front and Side views are in line horizontally.

Dimension Consistency

The depth of the Top view is the same as the depth of the Side view.

Dimension Consistency

The width of the Top view is the same as the width of the Front view.

Dimension Consistency

The height of the Side view is the same as the height of the Front view.

Top View Placement

A view taken from above; must be placed above the Front view.

Right Side View Placement

A view taken from the right; must be placed to the right of the Front view.

Left Side View Placement

A view taken from the left; must be placed to the left of the Front view.

Bottom View Placement

A view taken from below; must be placed below the Front view.

Glass Box Approach

A method for visualizing orthographic projection by placing the object in a theoretical glass box, freezing the view onto each of the six sides, and then unfolding the box.

Section View

A view used to show an area or hidden part of an object by cutting away or removing some of that object.

Cutting Plane

The cut line that indicates where the object has been removed or cut.

Full Section

The cutting plane line passes fully through the part. The section-lined areas are those portions that were

Half Section

Used to show the exterior and interior parts in the same view. The cutting plane cuts

Offset Section

Used to show parts and features that do not line up with each other. The cutting-plane line

Aligned Section

Used primarily on symmetrical circular parts. Parts and details are

Aligned Section (Ribs/Spokes)

Ribs and spokes can be left un-lined for better clarity.

Revolved/Removed Section

Used to show a cross-section of a small portion of a drawing, often turned 90 degrees (perpendicular) to the object.

Broken-out Section

Used to create a section for a small area without using a cutting-plane line. It removes a small amount of material to show interior details and is

Section Lining

The pattern of lines placed on the section view to indicate the portion of the object that was cut.

Section Lining Material (Common)

The symbol for cast iron can be used for most section views.

Cutting Plane Line (Function)

Indicates a plane or planes exposed by cutting and removing an imaginary section of the object.

Viewing Plane Line (Function)

Indicates the plane or planes from which a surface or several surfaces are viewed.