An example of the measurement of this
formula is shown in figure 2-12. When the exten-
sion is pointed back toward the handle of the
torque wrench, subtract the effective length of the
extension from the effective length of the torque
wrench. If the extension is pointed at a right angle
to the torque wrench, then the actual value does
not change.
An engineering study revealed a widespread
lack of understanding as to what happens when
an adapter is used with a torque wrench, To see
if you understand the effects of adapters and
extension handles, read the situation below and
answer the questions.
Figure 2-12.-Torque wrench with extensions.
Situation: Given a dial-indicating torque
wrench, an adapter, and an extension handle,
perform the following steps:
taken. If this is not done, the torque obtained will
be in error.
Torque a nut to a predetermined indicated
value, gripping the torque wrench at the end of
MICROMETERS.-- It is important that
the extension handle. Return to this torque value
a person repairing and building up engines
twice to ensure the nut is fully seated.
thoroughly understand the use, and care of the
m i c r o m e t e r . Micrometers are used to set
clearances and to measure damage or repair limits.
Remove the extension handle and apply the
Figure 2-13 shows an outside micrometer caliper
same indicated torque again.
w i t h the various parts clearly indicated.
Micrometers are used to measure distances to the
Question: Will the nut rotate before the
nearest one thousandth of an inch, The measure-
previously indicated torque is reached?
ment is usually expressed or written as a decimal.
You must know the method of writing and
Answer: Yes! Think it through--if you
reading decimals.
decrease the handle length (L), you increase the
Types of Micrometers. -- There are three types
torque (T) if the indicated torque (S) remains
of micrometers that are most commonly used
constant.
throughout the Navy. They are the outside
micrometer caliper (including the screw thread
Question: What would happen if a micrometer
micrometer), the inside micrometer, and the depth
torque wrench was used?
Answer: Nothing would change. The type of
torque wrench has no effect at all. It is simply a
function of the length of the lever arm between
the torque wrench square drive and where the
hands are placed on the handle.
Using solid-handle torque wrenches with
extension handles can cause significant over- or
undertorquing. This problem exists based on the
handle length chosen for the computation and
where hand force is actually applied on the
handle. When applying the formula, force must
be applied to the handle of the torque wrench at
Figure 2-13.-Nomenclature of an outside micrometer
caliper.
the point from which the measurements were
2-11