Technical Drawing Vocabulary


Terms in this set (...)

Center Line
A line which defines the center of arcs, circles, or symmetrical parts.
Construction Line
lightly drawn lines to guide drawing other lines and shapes.
A measurable extent, such as the three principal dimensions of an object is width, height, and depth.
Dimension Line
A line which represents distance.
Extension Line
Line which represents where a dimension starts and stops.
Hidden Line
A line type that represents an edge that is not directly visible.
Isometric Sketch
A form of pictorial sketch in which all three drawing axes form equal angles of 120 degrees with the plane of projection.
Leader Line
Line which indicates dimensions of arcs, circles and detail.
Long Break Line
A line which indicates that a very long objects with uniform detail is drawn foreshortened.
Multiview Drawing
A drawing which contains views of an object projected onto two or more orthographic planes.
Object Line
A heavy solid line used on a drawing to represent the outline of an object.
Oblique Sketch
A form of pictorial in which an object is represented as true width and height, but the depth can be any size and drawn at any angle.
Orthographic Projection
A method of representing three-dimensional objects on a plane having only length and breadth. Also referred to as Right Angle Projection.
Perspective Sketch
A form of pictorial sketch in which vanishing points are used to provide the depth and distortion that is seen with the human eye.
Projection Line
An imaginary line that is used to locate or project the corners, edges, and features of a three-dimensional object onto an imaginary two-dimensional surface.
Projection Plane
An imaginary surface between the object and the observer on which the view of the object is projected and drawn.
1. A straight-edged strip of rigid material marked at regular intervals that is used to measure distances. 2. A proportion between two sets of dimensions used to develop accurate, larger or smaller prototypes, or models.
Section Lines
Thin lines used in a section view to indicate where the cutting plane line has cut through material.
Vanishing Point
A point in space, usually located on the horizon, where parallel edges of an object appear to converge.