Tap extractors are straight and have prongs
damaged external or internal threads (fig. 3-9).
from end to end (fig. 3-10, view A). These
These tools are available to chase standard
extractors are available to remove broken taps
threads. The internal thread chaser has its cutting
ranging from 1/4 inch to 1 inch in outside
teeth located on a side face. The external thread
diameter. Spiral tapered extractors (fig. 3-10,
chaser has its cutting teeth on the end of the shaft.
view B) are sized to remove screws and bolts
The handle end of the tool shaft tapers to a point.
ranging from 3/16 inch to 3 l/2 inches in out-
SCREW AND TAP EXTRACTORS
Most sets of extractors include twist drills and
a drill guide. Tap extractors are similar to the
Screw extractors are used to remove broken
screw extractors and are sized to remove taps
screws without damaging the surrounding
ranging from 3/16 to 3 l/2 inches in outside
material or the threaded hole. Tap extractors are
used to remove broken taps.
You can retrieve small articles that have fallen
into places where you cannot reach them by hand
with the mechanical fingers. You can also use this
tool when starting nuts or bolts in difficult areas.
The mechanical fingers (fig. 3-11) have a tube
containing flat springs that extend from the end
of the tube to form clawlike fingers, much like
the screw holder. The springs are attached to a
rod that extends from the outer end of the tube.
A plate is attached to the end of the tube; a similar
plate, which you press with your thumb, is
attached to the end of the rod. A coil spring placed
around the rod between the two plates holds them
Figure 3-9.--Thread chasers.
Figure 3-10.--Tap and screw extractors.