Figure 4-29. Hinged Handle
Speed handle. The speed handle, shown
in figure 4-30, has a brace-type shaft with a revolving
grip on the top. It is used for rapid removal and/or
installation of nuts or bolts, which are out in the open
and have little or no torque.
Figure 4-30. Speed Handle
Hexagonal wrenches. Hexagonal setscrew
wrenches (Allen wrenches) are L-shaped, headless,
hexagonal bars that range in size from 3/64-to 1/2-inch.
A typical Allen wrench is shown in figure 4-31. They are
used in tightening or removing screws that have
Uses. When using any type wrench, special
attention should be given to choosing the one best
Figure 4-31. Hexagonal Setscrew Wrench (Allen
the job. Selecting a wrench larger than the nut or bolt
head will often result in rounded corners and additional
maintenance time. Arrange work so a wrench is pulled,
not pushed. Never use pipe or other extensions to
increase leverage. The following paragraphs describe
the various procedures involved with operating the
previously described wrenches.
Use of open-end wrenches. The 15-degree
offset of the jaws from the centerline of the wrench
makes the open-end wrench appropriate for use in some
applications where there is room to make only a part of
a complete turn of a nut or bolt. A typical procedure for
this application is shown in figure 4-32 and outlined in
Where conditions make it impossible to
use a socket or box-end, an open-end
wrench may be used. The open-end
wrench has fewer contact points than
either a socket or box-end and is more
likely to round off the corners of the nut.
Step 1 shows the wrench, with the
opening sloping to the left, about to be placed on the
Position the wrench on the nut (step 2).
Note that space for swinging the wrench is limited.
Move the wrench clockwise to tighten the
nut. The wrench will strike the casting which prevents
further movement (step 3).
Remove the wrench from the nut and turn
counterclockwise to place it on the next set of flats on