A self-locking nut fitted into a fitting hole of a reflector with which an aiming screw engages for adjusting an inclination angle of a reflector of a vehicular lamp, the self-locking nut comprising: a nut leading portion having slits extending in radius direction; a flange arranged below said nut leading portion; a fitting portion formed below said flange, said fitting portion having slits extending in radius direction and a pair of legs for fitting into the fitting hole of the reflector, said pair of legs being elastically expandable and having a wedge shape; a shaft hole having an inner surface, said shaft hole passing through the nut leading portion, the flange and the fitting portion in vertical direction; and a threaded portion formed on the inner surface of said shaft hole engageable with the aiming screw, the threaded portion comprising; first grooves extending from said slit of said fitting portion; second grooves positioned perpendicular to said slit of said fitting portion; a divided circumferential portion divided in the circumferential direction by said first and second grooves; and an entire circumferential portion having a circular shape in section, said entire circumferential portion being positioned at said fitting portion, wherein a pitch diameter of said entire circumferential portion being slightly smaller than that of the aiming screw.
13 Claims, 4 Drawing Sheets
