A bolt for peeling a coating film of the present invention includes notch parts 6 for peeling a coating film, the notch parts being formed over a plurality of pitches at top parts of screw threads in a male screw part 3 formed in a shaft part 2. The bolt is characterized in that the respective notch parts 6 formed over the plurality of pitches are arranged to be greatly inclined at an angle of 40° to 50° to an axial line 12 of the shaft part 2. Since the respective notch parts can be rolled sequentially, it is possible to form the notch parts 6 to be deeper and sharper than conventional ones and to enhance the coating film peeling performance. Also, the coating film peeled can be discharged efficiently as compared with conventional cases.

The objective is to provide a bolt which can more effectively suppress occurrence of seizure due to both oblique insertion and biting of foreign substances. The bolt includes a tapered surface, a guide portion, and a threaded portion in order from a distal end side and further includes a plurality of recesses provided on the tapered surface and a plurality of cutout portions provided at a distal end portion of the threaded portion.

A durable captive bolt assembly for use with subterranean utility boxes is described. The disclosed bolt assembly includes a fastener, a conical spring, a rigid washer, a deformable washer, and a bushing. The point and threads of the fastener are designed to clear debris from an internally threaded nut and reduce or eliminate cross threading, galling, and electrolysis.

An external screw member includes a parallel screw portion and a tapered screw portion provided on a side further toward a tip end than the parallel screw portion, and a plurality of sets of step portion and a transition screw thread portion are provided on at least one of the parallel screw portion and the tapered screw portion, the step portion having a reduced thread height in a radial direction and the transition screw thread portion gradually increasing in diameter from the step portion in an anti-driving rotation direction so as to reach a thread height of a normal screw thread portion. A top portion of the transition screw thread portion is positioned at an offset toward a pressure side relative to a position of a regular screw pitch in a minimum diameter portion of the step portion, and transitions to the regular screw pitch in the anti-driving rotation direction.

An external screw member includes a head, a shank, a parallel threaded portion, a tapered threaded portion, a screw thread, a convex portion and a screw driving side end face of the convex portion. The convex portion protruding more radially outward than the crest of the screw thread is formed in at least one of the parallel threaded portion and the tapered threaded portion over the tapered threaded portion and the parallel threaded portion. The screw driving side end face of the convex portion is configured to form an inclined plane which gradually rises from a root position of the end face at the side of the crest of the screw thread toward a crest of the convex portion in a direction opposite to a screw driving direction of the screw thread to reach the crest of the convex portion.

To threadedly engage a bolt and a female screw with each other, thereby making it possible to shave off a deposit on the inner surface of the female screw and to make it easy for a worker to sense the seating, there is provided a bolt including a shaft 2 and a head, wherein a first thread 11 is provided on a head side of the shaft, and at least one of a thread provided larger in diameter than the first thread and a thread provided wider than the first thread is provided on a tip end side of the shaft.

An external screw member includes a head, a shank, a parallel threaded portion, a tapered threaded portion, a screw thread, a convex portion and a screw driving side end face of the convex portion. The convex portion protruding more radially outward than the crest of the screw thread is formed in at least one of the parallel threaded portion and the tapered threaded portion over the tapered threaded portion and the parallel threaded portion. The screw driving side end face of the convex portion is configured to form an inclined plane which gradually rises from a root position of the end face at the side of the crest of the screw thread toward a crest of the convex portion in a direction opposite to a screw driving direction of the screw thread to reach the crest of the convex portion.

Various exemplary illustrations of a coating agent device are disclosed. In one example, a coating agent device may be a coating agent valve, e.g., for influencing the discharge of a coating agent. The coating agent device may include a plug-in or pluggable fastening base configured to facilitate a plug-in or pluggable mounting of the coating agent device. In some examples, the coating agent device may prevent relative rotation of the device relative to a mating component.

Various exemplary illustrations of a coating agent device are disclosed. In one example, a coating agent device may be a coating agent valve, e.g., for influencing the discharge of a coating agent. The coating agent device may include a plug-in or pluggable fastening base configured to facilitate a plug-in or pluggable mounting of the coating agent device. In some examples, the coating agent device may prevent relative rotation of the device relative to a mating component.

The objective is to provide a bolt which can more effectively suppress occurrence of seizure due to both oblique insertion and biting of foreign substances. The bolt includes a tapered surface, a guide portion, and a threaded portion in order from a distal end side and further includes a plurality of recesses provided on the tapered surface and a plurality of cutout portions provided at a distal end portion of the threaded portion.