01D-6
MECHANICAL INTRODUCTION
Tightening torques: General information
01D
If the length of the wrench is modified (extending the
handle, adapting an end piece) it is essential to recali-
brate the wrench to its new configuration.
Modifying the length of the wrench will modify its trigger
threshold.
Use the formula: C1 = CO x L2 / (L1+L2)
-CO: torque to apply,
-C1: adjustment torque to be displayed on the wrench,
-L1: length of the extension,
-L2: length of the wrench.
Unless there are special instructions in the repair meth-
od, a universal joint (CARDAN joint type) should be
used for measured tightening. Using a universal joint
will result in a difference between the set torque of the
wrench and the actual torque applied.
Before storing the wrench, loosen the adjustment
spring completely. A wrench stored with a spring under
tension will lose its tightening accuracy.
VII - PRECAUTIONS WHEN USING ELECTRONIC
TORQUE WRENCHES
An electronic torque wrench is a manual tightening
tool. The tightening torque and, depending on the mod-
el, the angle is read directly.
When used following best practises, the accuracy of
the tightness when using an electronic torque wrench
is ± 5%.
Electronic torque wrenches are not affected by the po-
sition of the operator's hand.It is advisable to handle the wrench with care and to
stop tightening when the required value is displayed on
the wrench.
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