Object Lines (A,
fig. 3-1). Object or Visiblel lines represent the visible edges
or outlines of an object.
Hidden Lines (A,
fig. 3-1). Hidden lines are made of short dashes which represent
hidden edges of an object.
Center Lines (B,
fig. 3-1). Center lines are made with alternating short and long
dashes. A line through the center of an object is called a center
Cutting Plane Lines
(B, fig. 3-1). Cutting plane lines are dashed lines, generally
of the same width as the full lines, extending through the area
being cut. Short solid wing lines at each end of the cutting line
project at 90 degrees to that line and end in arrowheads which
point in the direction of viewing. Capital letters or numerals
are placed just beyond the points of the arrows to designate the
Dimension Lines (A,
fig. 3-1). Dimension lines are fine full lines ending in arrowheads.
They are used to indicate the measured distance between two points.
Extension Lines (A,
fig. 3-1). Extension lines are fine lines from the outside edges
or intermediate points of a drawn object. They indicate the limits
of dimension lines.
Break Lines (C, fig.
3-1). Break lines are used to show a break in a drawing and are
used when it is desired to increase the scale of a drawing of
uniform cross section while showing the true size by dimension
lines. There are two kinds of break lines: short break and long
break. Short break lines are usually heavy, wavy, semiparallel
lines cutting off the object outline across a uniform section.
Long break lines are long dash parallel lines with each long dash
in the line connected to the next by a "2" or sharp
THE POWER POINT PRESENTATION