General
1-17
Torque Wrenches
Use a torque wrench with a socket,
torque adapter or similar extension to
tighten a fastener to a measured torque.
Torque wrenches come in several drive
sizes (1/4, 3/8, 1/2 and 3/4) and have
various methods of reading the torque
value. The drive size indicates the size
of the square drive that accepts the
socket, adapter or extension. Common
methods of reading the torque value are
the deflecting beam, the dial indicator
and the audible click (Figure 12).
When choosing a torque wrench,
consider the torque range, drive size and
accuracy. The torque specifications in
this manual provide an indication of the
range required. A torque wrench is a
precision tool that must be properly
cared for to remain accurate. Store
torque wrenches unloaded in cases or
separate padded drawers within a
toolbox. Follow the manufacturer’s
instructions for their care and calibration.
Torque Adapters
Torque adapters or extensions extend or
reduce the reach of a torque wrench.
The torque adapter shown in (Figure 13)
is used to tighten a fastener that cannot
be reached because of the size of the
torque wrench head, drive, and socket.
If a torque adapter changes the effective lever
length (Figure 14), the torque reading on the
wrench will not equal the actual torque
applied to the fastener. It is necessary to
recalibrate the torque setting on the wrench to
compensate for the change of lever length.
When using a torque adapter at a right angle
to the drive head, calibration is not required,
because the effective length has not
changed. To recalculate a torque reading
when using a torque adapter, use the
following formula and refer to Figure 14: