Figure 4-33. Use of Box-End Wrench
The corner of the casting may prevent the
wrench from fitting on the nut (step 4).
If this occurs, flip the wrench over so that
the opening will slope to the right (step 5).
Position the wrench on the next two flats
on the nut (step 6).
Figure 4-34. Use of Socket Wrench
Turn the wrench clockwise to further
tighten the nut (step 7).
Continue flipping the wrench as required
until the nut is completely tightened.
Use of box-end wrenches. Box-end wrenches
are very good for final tightening of nuts. The following
procedures describe the typical use of box-end
Select the size of wrench that fits the nut
Place the wrench on the nut or bolt and
turn as required to loosen or tighten.
If there is insufficient room to swing the
wrench in a full circle, as shown in figure 4-33, lift it
completely off the nut when it comes to the limit of the
swing, and place it in a new position, permitting another
swing. A swing through a 15-degree arc is usually
sufficient to continuously loosen or tighten a nut or bolt.
Use of socket wrenches. Where practical, a
socket wrench is best of loosening or tightening nuts and
bolts. Speed can be attained through the use of
ratchets and speed handles. Length of the handle used
is very important, as very little pressure is required to
strip threads of twist off a small bolt using a long handle.
Extension bars and universal joints enable a mechanic
to get at nuts or bolts that would otherwise be out of
reach or at a difficult angle. Figure 4-34 shows a typical
use of a ratchet wrench. The procedure is outlined as
Select the size of the socket that fits the
nut or bolt to be turned. Push it onto the handle which is
best suited for the job.
Turn the socket with the handle to tighten
or loosen the nut or bolt.
Use of adjustable wrenches.
wrenches should be used only when wrenches of correct
size are unavailable. They should be properly adjusted
and pulled so the handle moves in the direction of the
adjustable jaw, as shown in figure 4-35. Place the
wrench on the nut so that the force used to turn it is
applied to the stationary jaw side of the wrench
Repair. Some repair is possible to certain types
of wrenches. Wrenches can damage nuts and bolts if
the fit is not just right. Generally speaking, repair of