ADHESIVES | THREADLOCKING
LOCKED IN How to achieve the best clamp load retention
performance in extreme conditions.
Threaded assemblies
are the most important
detachable parts
used in machinery
construction, installation and
repair. Relaxation of tension and
self-loosening is common for any
machine but when it is operating
in harsh environments, the need
to minimise this deterioration with
effective threadlocking is even
more important. Various methods
are available but what are their
respective strengths and failings?
Mechanical devices such as
split pins and tab washers are only
suitable for preventing the loss of
nuts and bolts. Friction devices
give some resistance to vibration
but do not perform well under
extreme conditions. Locking
devices, such as tooth anged and
ribbed anged bolts, nuts and
washers are effective at preventing
self-loosening but can damage
the contact surface, need larger
ange-bearing surfaces and are
expensive.
Increasingly, threadlocking
adhesives are taking the place of
traditional mechanical locking
devices because they deliver
the greatest all-round ef ciency,
especially when the going gets
tough. As well as preventing
unwanted movement, loosening,
leaks and corrosion, they resist
vibration. They are free- owing
liquids or semi-solid adhesives
that completely ll the gaps
between mating threads of
fasteners and joints.
PROOF POSITIVE
To prove the performance of its
threadlocking system against other
methods, Loctite submitted its
products for independent testing
in a transverse shock and vibration
machine in which pneumatic
hammers force relative movement
of the stressed parts. At the same
time, the existing pre-stress force
was continuously measured
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