Abstract: Disclosed is a synthetic resin grommet comprising a head portion having a screw insert hole, a bottom cylindrical portion having a cylindrical hole, and a pair of locking claws. With this arrangement, the syntheric resin grommet can improves its water-proof property.

Abstract: Disclosed is a bolt which comprises a short column portion formed at the extreme end of the thread portion thereof, wherein the short column portion has a diameter larger than the root diameter of the thread portion and smaller than the thread diameter thereof and the extreme end thereof is formed to a spherical portion and a method of manufacturing the bolt by which a thread portion and a spherical surface portion are simultaneously rolled. The bolt arranged as described above has an excellent guide property to a nut.

Abstract: A grommet for automatic insertion into a mounting hole in a panel by a robot including a head portion 1 having a longitudinal bore for receiving a screw through its center, a bottom portion 3 including a stepped portion 7 elastically engaging the robot arm located within the longitudinal bore; and locking claws 4 attached to the grommet which reflect during insertion of the grommet into the mounting hole and then spring snap into engagement when the locking claws 4 clear the mounting hole, such that the force required to disengage the robot arm 5 from the stepped portion 7 is less than the force required to extract the grommet from the panel, which enables the robot to easily determine whether or not the grommet is accurately inserted into the mounting hole.

Abstract: Disclosed is a stud bolt having nonsymmetrical screw threads projecting from the shank thereof, wherein each screw thread of the stud bolt has an inwardly concave curved flank and an outwardly convex curved flank. With this arrangement, the load required to fit a resin clip over the stud bolt can be lowered below that needed for a conventional stud bolt while maintaining the load required to remove the clip equal to or more than that for the conventional bolt. Thus, this stud bolt allows a resin clip to be easily fitted over the bolt.

Abstract: A hexagon head bolt having a head with an incline formed on each of the outer faces thereof so as to be inwardly inclined toward a respective corner of each face. Thus the head of the bolt can easily be engaged with the socket of an impact wrench or the like, without damage of the corners of the bolt. In another embodiment, a hexagon socket is provided having an incline formed on each of the outer faces thereof so as to be outwardly inclined toward a respective corner of each face.

Abstract: A self-aligning bolt has an eccentric pilot tip extending forwardly of the externally threaded shank thereof. A self-aligning nut has an eccentric counter-bore formed therein on the side of the seating face and offset from the axis of the internally threaded bore of the nut.

Abstract: A cover of synthetic resin is formed within a stepped recess of a nut adjacent the upper end of the internally threaded portion by injection molding. The cover includes a ring-like mounting frame positioned in the stepped recess, and a covering plate positioned inside the ring-like mounting frame and connected to it by a hinge portion of the cover. The ring-like mounting frame have an integral portion provided at the lower portion of the frame and firmly engaging a portion of the inner surface of the internally threaded portion.