LOOSENING PREVENTION STRUCTURE FOR BOLT AND NUT

摘要

Provided is a loosening preventive structure for a bolt and nut, comprising a bolt, a nut member to be threadably engaged with the bolt and a lock nut. Said nut member has a lock nut engaging section made in a tapering shape extending axially toward one end thereof. The lock nut engaging section includes a male thread defined in an exterior circumferential wall in the identical or the inverse threading direction relative to a female thread defined in the interior circumferential wall and also includes a slit extending axially toward the one end thereof.