To provide an axial force controlling nut assembly capable of suppressing coarsening and abrasion of a nut seat face, and easily certifying whether or not proper axial force has been reached.
The axial force controlling nut assembly 10 is provided with a seat member 11, a fastening nut 12 turned relatively to the seat member, and a ring assembly 13 interposed between the seat member and the fastening nut. The ring assembly 13 includes one or more rings, and at least one ring thereof is an axial force controlling ring 20 capable of turning freely before bolt axial force becomes the proper axial force, and constrained from turning when the bolt axial force becomes the proper axial force or more. The ring assembly includes an elastic deformation ring 21, there is a gap between an outer circumference part of the elastic deformation ring 21 and the seat member 11 before the bolt axial force becomes the proper axial force, and the gap between the outer circumference part of the elastic deformation ring 21 and the seat member 11 becomes zero when the bolt axial force becomes the proper axial force or more.
KIMURA YOSHIMASA
MIYASHITA SATORU
KODAMA SHOICHIRO
