Figure 1-10.-Torque wrenches.
steady motion. (A fast or jerky motion will result in
an improperly torqued unit.) When the torque applied
reaches the torque value, which is indicated on the
handle setting, a signal mechanism will automatically
issue an audible click, and the handle will release or
break, and move freely for a short distance. The
release and free travel is easily felt, so there is no
doubt about when the torquing process is complete.
Manufacturers and technical manuals generally
specify the amount of torque to the applied. To
assure getting the correct amount of torque on the
fasteners, it is important that the wrench be used
properly according to manufacturers instructions.
Use the torque wrench that will read about
mid-range for the amount of torque to be applied. BE
SURE THE TORQUE WRENCH HAS BEEN
CALIBRATED BEFORE YOU USE IT. Remember,
too, that the accuracy of torque-measuring depends a
lot on how the threads are cut and the cleanliness of
the threads. Make sure you inspect and clean the
If the manufacturer specifies a thread
lubricant, it must be used to obtain the most accurate
torque reading. When using the deflecting beam or
dial indicating wrenches, hold the torque at the desired
value until the reading is steady.
Torque wrenches are delicate and expensive tools.
The following precautions should be observed when
1. When using the micrometer setting type, do
not move the setting handle below the lowest torque
setting. However, it should be placed at its lowest
setting before it is returned to storage.
2. Do not use the torque wrench to apply greater
amounts of torque than its rated capacity.
3. Do not use the torque wrench to loosen bolts
that have been previously tightened.
4. Do not drop the wrench. If a torque wrench
is dropped, its accuracy will be affected.
5. Do not apply a torque wrench to a nut that
has been tightened. Back off the nut one turn with a
nontorque wrench and retighten to the correct torque
with the indicating torque wrench.
6. Calibration intervals have been established for
all torque tools used in the Navy. When a tool is
calibrated by a qualified calibration activity at a
shipyard, tender, or repair ship, a label showing the
next calibration due date is attached to the handle.
This date should be checked before a torque tool is
used to ensure that it is not overdue for calibration.
A handy all-round wrench that is generally
included in every toolbox is the adjustable open-end
wrench. This wrench is not intended to take the place
of the regular solid open-end wrench. Additionally, it