Abstract: 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.

Abstract: 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.

Abstract: There is provided a caulking bolt which can be fastened by a general nut even when used to fix thin plates to each other, and which can also provide fitting strength similar to that of conventional products. The caulking bolt includes a head part and a shaft part, and has a non-circular, flat, rotation preventive protrusion formed on a seat surface of the head part. Also, the upper end of a normal complete thread part formed in the shaft part is brought close to the seat surface of the head part with a distance of 3 pitches or less, and an incomplete thread part formed at the portion of 3 pitches or less is used as a stopper part into which a metal flows when the caulking bolt is driven into a metal plate.

Abstract: There is provided a caulking bolt which can be fastened by a general nut even when used to fix thin plates to each other, and which can also provide fitting strength similar to that of conventional products. The caulking bolt includes a head part 11 and a shaft part 12, and has a non-circular, flat, rotation preventive protrusion 14 formed on a seat surface 13 of the head part. Also, the upper end of a normal complete thread part 17 formed in the shaft part 12 is brought close to the seat surface 13 of the head part with a distance of 3 pitches or less, and an incomplete thread part 18 formed at the portion of 3 pitches or less is used as a stopper part into which a metal flows when the caulking bolt is driven into a metal plate.