The Junker vibration test to DIN 65151 is an excellent
method for testing and comparing the security of
bolted joints. During the test, the joint is subjected
to transverse movements while the tension is being
continuously measured by a load cell.
The Junker test shows that Nord-Lock washers safely secured
the bolted connection; only a limited amount of tension is
initially lost due to normal settlements. The wedge-locking
function is verified through the clear increase in tension
during untightening. All other bolt locking methods in the
test failed to prevent loosening of the joint.