PRIN. OF DRAFTING AND SHOP DRAWINGS - OD1641 - LESSON 1/TASK 4
A piece is "broken cut," therefore, and the object is drawn full size.
The methods used to indicate this are termed "conventional breaks." Figure 86 shows
some of the most common of these.
Shop Terms--Drilling, Reaming, Counterboring, and Countersinking
Drilling, reaming, counterboring, and countersinking are very common machining
operations that are called for on a drawing by a drawing note. Each operation is
defined in the following subparagraphs and illustrated in figure 87 (on the
a. Drilling. Drilling is a machine operation that produces holes. The bottom of
drilled holes are drawn to a 30,-tapered point as shown in figure 87, view A.