WOODWORKING
Hidden Lines Thin, Medium Dashed Line
There are times when an object is hidden from view. Meaning, it is
behind or inside the object being drawn. This object still must be
shown. To do so, hidden lines are incorporated. They are drawn
just like an object line, only not as thick and with dashes. In the
case of the CD rack on the right, the parts constructed to hold the
CDs cannot be seen from the side view, so we use hidden lines to
show they are there. Never use dimension lines on hidden objects.
Section Lines Heavy, Dark Broken Line
Sometimes it is necessary to show the inside of an object. In this case we use what is called a section
line. Section lines are heavy, dark broken lines with an arrow on one end and a section symbol on the
other. Think of it as a visual cut line. In essence, the section line tells the manufactorer where you as
the draftsman will cut open the object and show the inside to provide necessary information. Section
lines may be placed on the front view, top view, or side view. In the case of our CD holder, the racks
cannot be seen from the side view, so we place a section line on the top view to indicate we’ve drawn
an inside view (a section) of the object.
Line Quality:
Drafting plans are drawn instructions of how something is manufactured. As such, they must be easily
understood. Like any instructional material, if you can’t read it, it’s no good. Line quality is one method
used to insure the readability of your plans. Remember, drafting is an art form, but it is a technical art
form. That being said, no sloppy lines are allowed. Line quality has to do with clean, crisp, and sharp
lines. Corners do not over extend, arcs have a tangent, and circles have a center. The lines are uniform,
dimensions do not crowd the object, and dimension lines are always parallel to the object measured. Keep
your pencil sharp, keep your lines straight, and use the correct line type.
Drafting
