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 in cases or separate padded drawers
within a toolbox. Follow the manufacturer’s in-
structions for their care and calibration.
Torque Adapters
Torque adapters extend or reduce the reach of a
torque wrench. The torque adapter shown in
Figure
20
is used to tighten a fastener that cannot be
reached due to the size of the torque wrench head,
drive, and socket. Since a torque adapter changes
the effective lever length (
Figure 21
) of a torque
wrench, the torque reading on the wrench does not
equal the actual torque applied to the fastener. It is
necessary to calculate the adjusted torque reading
on the wrench to compensate for the change of lever
length. When a torque adapter is used at a right an-
gle to the drive head, calibration is not required,
since the effective length has not changed.
To calculate the adjusted torque reading when us-
ing a torque adapter, use the following formula.
TW = TA × L
L + A
TW
is the torque setting or dial reading on the
wrench.
TA
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 reduces) the effective lever length as
measured along the centerline of the torque wrench
from the center of the drive to the center of adapter
box end (
Figure 21
).
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 is mea-
sured along the centerline of the torque wrench as is
the sum of
L
and
A
. For example:
To apply 20 ft.-lb. to a fastener using an adapter
as shown in the top example in
Figure 21
.
TA = 20 ft.-lb.
A = 3 in.
L = 14 in.
TW = 20 × 14 = 280 = 16.5 ft. lb.
14 + 3
17
In this example, a click-type torque wrench
would be set to the calculated torque value (TW =
16.5 ft.-lb.) . When using a dial or beam-type torque
wrench, tighten the fastener until the pointer aligns
with 16.5 ft.-lb. In either case, although the torque
wrench reads 16.5 ft.-lb., the actual torque applied
to the fastener 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
22
shows several types of useful pliers. Each design
has a specialized function. Slip-joint pliers are gen-
eral-purpose pliers used for gripping and bending.
Diagonal cutting pliers cut wire and can be used to
remove cotter pins. Adjustable pliers can be ad-
justed to hold different size objects. The jaws re-
main parallel so they grip around objects such as
pipe or tubing. Needlenose pliers are used to hold or
bend small objects. Locking pliers (
Figure 23
),
sometimes called vise-grips, are used to hold ob-
jects 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
12
CHAPTER ONE
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