Alphabet of Lines

ALPHABET OF LINES Lines are the critical component

of sketching Lines have different types,

thickness and shape has its own meaning

Alphabet of Lines are also known as “Line symbols”

OBJECT OR VISIBLE LINE Thick, dark line used to show

the outline of the object. Define features you can see in a particular view

CONSTRUCTION LINE Lines that are very light and

very thin use to construct layout work

DIMENSION LINE Thin and dark lines use to show

the size (span) of an object with a numeric value. Usually terminates with arrowheads or tick markings.

HIDDEN LINE Short dash lines use to show non

visible surfaces that are not visible in orthographic view. Usually shows as medium thickness.

CENTRE LINE Long and shot dash lines.

Usually indicates centre of holes, circles and arcs. Line is thin and dark.

EXTENSION LINE A light line that extends from the

edge or end of a main object line on a drawing, used in conjunction with dimension lines to help determine the dimension of a particular feature.

CUTTING PLANE LINE Extra thick line use to show

cutaway views or plane of projection where a section view is taken. Arrow indicates direction of view.

LEADER LINE A thin line used to connect a

dimension line with a particular area or point on the drawing. It is also use to show notes or labels.

PHANTOM LINE Long line followed by two short

dashes use to show alternate position of a moving part.

SHORT-BREAK LINE Thick wavy line that is used to

break the edge of a surface of a part for clarity on a hidden surface

LONG-BREAK LINE Long, thin lines that is used to

show that the middle section of an object has been removed so it can be drawn on a smaller piece of paper