Figure 4-13.--Angle-drive drills.
chuck normally requires a wrench to tighten the jaws or
Figure 4-12.--Pneumatic drills.
it may require a special threaded drill bit.
into the air supply. The two most used types are the
straight and the pistol grip. See figure 4-12.
Special tools are not normally part of an
individual's toolbox. These tools are normally
The angle-drive drills are attached to the drill motor
maintained in a central tool room and signed out when
by an adapter assembly or clamped into the existing
drill chuck. They are available with a ridged or flexible
drive shaft and come in several different head angles.
Dimple Countersinking Tools
See figure 4-13. These units are designed to be used as
Dimple countersinking is accomplished by using
an extension of the drill motor in hard to reach areas.
male and female dies. The female die, shown in figure
The drill motor should never be started unless you have
4-14, contains a spring-loaded ram that flattens the
positive control of the angle-drive unit. The flexible
bottom of the dimple as it is formed. This prevents
shaft is commonly referred to as a snake drill. The drill
Figure 4-14.--Dimple countersinking.