ADDA General Drafting Terminology

Multiply inches by 25.4

An angle of less than 90°

Any portion of the circumference of a circle.

Any straight line whose opposite ends terminate on thecircumference of a circle

Two angles whose sum is 90°

The distance across a circle passing through its center

A triangle with three equal sides and threeequal angles

A triangle with two equal sides and two equalangles

The long axis of an ellipse

The short axis of an ellipse

The distance from the center point of a circle to theoutside circumference

An angle greater than 90°

A triangle with one 90° angle

Two angles whose sum is 180°

A figure bounding so as to touch in as manyplaces possible

A figure encircled so as to touch in as many placespossible

At 90° to a given plane or line

A quality in which all the features on either side ofa point, line or a plane are identical

A part of a whole, such as ½ or ¼

1:2

2:1

Drawing an object to a set proportion such as ½, ¼or double its actual size

A decimal system of weights and measures basedon the meter and the kilogram

A slanted surface not at 90° to another surface

A beveled corner at the opening of a hole or the end ofa cylindrical part to eliminate sharp edges

An interior corner found on cast, forged or molded parts

A diamond shaped or parallel pattern cut into cylindricalsurfaced to improve gripping or bonding between parts

An exterior corner found on cast, forged or molded parts

Lines that are equidistant/non-intersecting

Lines that are non-intersecting, non-parallel in 3-Dspace

A plane figure bounded by four straight sides

Two sides parallel

A foreshortened circle having a major and a minor axis

To divide into two equal parts

¼ of a circle