Yamaha MM700A Manual page 17

GENERAL INFORMATION
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 prop-
erly cared for to remain accurate. Store torque wrenches in
cases or separate padded drawers within a toolbox. Fol-
low the manufacturer's instructions for their care and cali-
bration.
Torque Adapters
Torque adapters or extensions extend or reduce the
reach of a torque wrench. The torque adapter shown in
Figure 18 is used to tighten a fastener that cannot be
reached due to the size of the torque wrench head, drive,
and socket. If a torque adapter changes the effective lever
length (Figure 191), 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. calibra-
tion is not required, since the effective length has not
changed.
To recalculate a torque reading when using a torque
adapter, use the following formula, and refer to Figure 18.
TW is the torque setting or dial reading on the
is the torque specification and the actual
amount of torque that will be applied to the fastener. A is
the amount that the adapter increases (or in some cases re-
duces) the effective lever length as measured along the
centerline of the torque wrench (Figure 19). L is the lever
length of the wrench as measured from the center of the
drive to the center of the grip. The effective length of the
torque wrench measured along the centerline of the torque
wrench is the sum of L and A (Figure 19).
Example:
TA 20
A = 3 in.
14 in.
TW 20 x 14
16.5 ft. Lb.
=
17
=
In this example, the torque wrench would be set to the
recalculated torque value (TW
a beam-type wrench, tighten the fastener until the pointer
aligns with 16.5 ft.-lb. In this example, although the
torque wrench is pre-set to 16.5 ft.-lb., the actual torque is
20 ft.-lb.
Pliers
Pliers come in a wide range of types and sizes. Pliers are
useful for holding, cutting, bending, and crimping. Do not
use them to turn fasteners. Figure 20 and Figure 21 show
several types of useful pliers. Each design has a special-
ized function. Slip-joint pliers are general-purpose pliers
used for gripping and bending. Diagonal cutting pliers are
needed to cut wire and can be used to remove cotter pins.
Needlenose pliers are used to hold or bend small objects.
Locking pliers (Figure 21), sometimes called vise-grips,
are used to hold objects very tightly. They have many uses
ranging from holding two parts together, to gripping the
end of a broken stud. Use caution when using locking pli-
ers, as the sharp jaws will damage the objects they hold.
16.5 ft.-lb.). When using
=