Abstract: A stud bolt is provided that can improve the quality obtained when being fixed to a mounting target plate. [Means for Resolution] A stud bolt B to be fixed, in a retained state and a rotation stop state, to a mounting target plate T includes a head 1, a screw shaft portion 2, a rotation stop portion 3, an annular groove 21, and an annular protrusion 22. The mounting target plate T is to be sandwiched between a bearing surface 21 of the head 1 and the annular protrusion 22. A recessed portion 32 recessed toward an upstream side X2 in a screw advance direction is formed at the rotation stop portion 3.

Abstract: A self-tapping including a normal thread (10) and a female screw molding thread (12) having a larger diameter than that of the normal thread (10), out of pitches of the normal thread (10) positioned in a head portion side from the female screw molding thread (12), any one pitch is set to be larger than other pitches. The self-tapping not only reduces driving torques but also improves fastening force, and thus can be applied to various workpieces made of the soft material as well as a hard material.

Abstract: A locking screw including a male screw and a female screw, the male screw being screwed into the female screw, the male screw including male threads and the female screw comprising female threads, wherein a male thread comprises a crest side flank surface and a root side flank surface connecting the crest side flank surface and a root of the male thread, a slope of the crest side flank surface is smaller than a slope of a female flank surface of the female thread, a slope of the root side flank surface is larger than the slope of the female flank surface, a connected portion of the crest side flank surface and the root side flank surface interferes with the female thread, and a clearance is formed between the root side flank surface and the female screw when the connected portion interferes with the female thread.

Abstract: There is provided a tapping screw having a high anti-loosening effect and a high pull-out resistance for resin-molded components. A tapping screw 1 according to the present invention is configured such that an intersection P between a root 10 and a clearance flank 8 of a thread 7 is set such that a first engaging rate ?1 exceeds 50%, the first engaging rate ?1 being percentage of an actual engaging height H1 to a hole 6 against a first thread height H2 from a crest of the, thread 7 to the intersection P, an intersection Q between the root 10 and a pressure flank 9 of the thread 7 is set such that a second engaging rate ?2 is smaller than the first engaging rate ?1 and no smaller than 50%, the second engaging rate ?2 being percentage of the actual engaging height H1 to the hole 6 against a second thread height H3 from the crest of the thread 7 to the intersection Q, and the root of the thread inclines downward toward a tip direction, extending from the intersection P to the intersection Q thus set.

Abstract: [Object] To provide a self-tapping screw which is the most suitable for tightening a workpiece made of a soft material such as a resin or an aluminum alloy. [Solution] In the self-tapping screw 1 including a normal thread 10 and a female screw molding thread 12 having a larger diameter than that of the normal thread 10, out of pitches of the normal thread 10 positioned in a head portion side from the female screw molding thread 12, any one pitch is set to be larger than other pitches. The self-tapping screw 1 not only reduces driving torques but also improves fastening force, and thus can be applied to various workpieces made of the soft material as well as a hard material.

Abstract: A locking screw includes a head and a leg that has a thread formed thereat. The screw is screwed into a female screw hole, at which a female screw is formed. An angle formed by flank surfaces on a root side of a male screw is smaller than an angle formed by flank surfaces constituting the female screw whereas a vertex formed by the flank surfaces on the crest side of the male screw is an obtuse angle greater than 90°. Furthermore, the flank surface on the root side and the flank surface on the crest side are connected to each other via an arcuate surface. The width of the crest of the male screw is greater than the width of the root of the female screw mating with the crest of the male screw. The resultant locking screw can exhibit a locking function on the thread crest side of the male screw. The male screw can be efficiently brought into contact with the female screw-so as to-interfere therewith, thus securely inhibiting the male screw from being loosened.