Doosan DX180LC, Shop Manual

Page: 101 / 110

SP000017
Page 13
Standard Torques
NOTE:
The formula assumes that there is no added
deflection or "give" in the joint between the extension
and torque wrench. Readings may also be
inaccurate:
• If the extension itself absorbs some of the tightening
force and starts to bend or bow out.
• If an extension has to be fabricated that is not straight
(for example, an extension made to go around an
obstruction, to allow access to a difficult to tighten
fastener), the materials and methods used must be
solid enough to transmit full tightening torque.
Other Uses for Torque Wrench Extension
Tools
Torque wrench extensions are sometimes made up for reasons
other than increasing leverage on a fastener.
For example, a torque wrench and extension can be used to
measure adjustment "tightness" of a linkage or assembly.
Specially fabricated extensions can be used to make very
precise checks of the force required to engage or disengage a
clutch mechanism, release a spring-applied brake assembly, or
"take up" free play in most any movable linkage.
Once the value of the adjustment force is established, repeated
checks at regular intervals can help to monitor and maintain
peak operating efficiency. These types of adjustment checks are
especially useful if physical measurements of linkage travel are
difficult to make or will not provide the needed degree of
precision and accuracy.
To allow the assembly or mechanism to accept a torque wrench,
welding a nut or other adapter on the end of a linkage shaft or
other leverage point will allow turning the shaft or assembly
manually.
Tightening Torque Specifications (Metric)
(For coated threads, prelubricated assemblies.)