An Evaluation Test for Influences of the Paint-film Upon Self-loosening of Fasteners
Yasuo SATOH, Takafumi NAGATOMO, Hiroto MACHIDA, Saburoh ENDOH,
Takafumi ENARI, Katsuya KIRIMURA, Takehiko KIGAWA
Experiments are carried out for evaluating the influences of the paint-film
upon self-loosening of fasteners. Two kinds of paint, i.e. alkyd paint system
and etching primer, are used in the test. The evaluation was carried out in terms
of the relationship between the rotation angle and the axial tension from the
onset of tightening stage to the end of vibrating stage of the tightened specimen.
A thicker paint-film of alkyd paint system gives rise to a remarkable reduction
of axial tension after tightening. Furthermore, the vibration accelerates this
reduction causing a considerable self-rotation. Paint-film of etching primer
brings about less reduction of axial tension and the self-rotation is not observed
at all even in the vibrating stage.