Sometimes the technical information conveyed by a drawing can best be shown by a view that represents the object as it would look if part of it were cut away. A view of this kind is called a section.

The upper view of figure 3-37 shows a plan view of a pipe sleeve. The lower view is a section,

Figure 3-37.-Drawing of a plan view and a full section.

showing the pipe sleeve as it would look, viewed from one side, if it were cut exactly in half vertically. The surface of the imaginary cut is crosshatched with lines called section lines. According to DoD-STD-100C, "section lining shall be composed of uniformly spaced lines at an angle of 45 degrees to the baseline of the section. On adjacent parts, the lines shall be drawn in opposite directions. On a third part, adjacent to two other parts, the section lining shall be drawn at an angle of 30 to 60 degrees." The cross-hatching shown in figure 3-37 could be used on any drawing of parts made of only one material (like machine parts, for example, which are generally made of metal). The cross-hatching is the symbol for metals and may be used for a section drawing of any type of material.

A section like the one shown in figure 3-37, which goes all the way through and divides the object into halves, is called a full section. If the section showed the sleeve as it would look if cut vertically into unequal parts, or cut only part way through, it would be a partial section. If the cut followed one vertical line part of the way down and then was offset to a different line, it would be an offset section.