Chapter 8 Power Tools 191
Copyright Goodheart-Willcox Co., Inc.
similar to those that attach to ratchet handles used by
mechanics, but they are made of much stronger steel. In
fact, impact sockets may be used with standard socket
wrench sets, but standard sockets are not engineered
to withstand the hammering effect of an impact driver.
When impact sockets are paired with an impact driver,
the combination is often referred to as an impact wrench.
See Figure 8-13.
The second type of impact driver looks like a
stubby-bodied power drill equipped with a quick-
connect hexagonal socket to accept an assortment
of screwdriver bits, nut drivers, drills, and other
attachments. See Figure 8-14. For general construction
and most do-it-yourself work, this type of impact
driver is indispensable. Driving screws with an impact
driver and a screwdriver bit has replaced the use
of a hammer and nails for many applications. The
development of long-lasting, powerful lithium-ion
batteries has also greatly increased the effectiveness
and popularity of these tools.
Drill Presses
Most well-equipped shops include a stationary
drill press, Figure 8-15. Drill presses are large, variable-
speed power drills mounted to a vertical stabilizing
shaft. The shaft and drill assembly are attached to a
base with an adjustable table for securing workpieces.
Using a drill press instead of a portable power drill
helps to increase the precision of the alignment and
angle of holes. It can also safely apply much more force
because the workpiece can be clamped to the table,
and the motion of the spindle and the bit is stabilized
through its attachment to the column, or frame, of the
drill press.
Floor-mounted and benchtop drill press models
are available. The size of a drill press is determined
by the maximum diameter of the work material that
can be drilled exactly in the center. The size may be
checked by measuring from the center of a chuck-
mounted bit to the closest location on the column and
doubling that measurement. For example, a drill press
that is 7″ from center to column is a 14″ drill press.
This press is capable of drilling a hole in the center
of material with a maximum 14″ diameter.
A Jacobs chuck is the common way of attaching bits to smaller drill
presses. Some larger drill presses accept Morse taper shank bits. A Morse
taper is a tapered shank that holds the drill bit entirely by the friction
Yotsatorn Laonalonglit/Shutterstock.com
Figure 8-13. Pneumatic impact wrenches use
heavy-duty sockets to loosen and tighten fasteners.
OlegSam/Shutterstock.com
Figure 8-14. Cordless impact drivers can be very
powerful and are usually more compact than
cordless drills. Note the quick-connect hexagonal
socket to accept different bits.