Abstract: An indexable thread forming tap including: a body in a shaft shape; and a tip concentrically and detachably attached to a leading end portion of the body by screw-fastening and rotationally driven around an axial center along with the body for rolling of a female thread, the body being disposed with a screw hole concentrically to the axial center such that a screw shaft disposed on the tip concentrically to the axial center is screwed into the screw hole for the screw-fastening, a leading end surface of the screw shaft being pressed against a bottom surface of the screw hole into close contact with each other by the screw-fastening to integrally fix the tip to the body without the leading end of the body abutting on the tip, the body being disposed with a restraining hole concentrically to the axial center.

Abstract: A variable lead end mill has a plurality of peripheral cutting edges with different helix angles, the variable lead end mill having a flute bottom diameter of a plurality of helix flutes making up rake faces of the plurality of the peripheral cutting edges, the flute bottom diameter increasing in an axial direction from a tool tip toward a shank.

Abstract: A removable tip type rotary tool is provided in which a rotation stop key and a key groove each having a triangular shape are disposed on opposing surfaces of a body and a tip concentrically attached to a leading end portion of the body in a removable manner. A pair of side surfaces of the rotation stop key and a pair of side walls of the key groove are brought into surface contact by mounting screw. An angle for each of the pair of the side surfaces and the pair of side walls is between 60 to 100 degrees, a groove bottom of the key groove is rounded with a radius from 1.5 to 2.8 mm, corners of opening edges on both sides of the key groove and corners of both base-end side portions of the rotation stop key are rounded with radiuses, respectively, from 1.5 to 2.8 mm.

Abstract: An indexable thread forming tap including: a body in a shaft shape; and a tip concentrically and detachably attached to a leading end portion of the body by screw-fastening and rotationally driven around an axial center along with the body for rolling of a female thread, the body being disposed with a screw hole concentrically to the axial center such that a screw shaft disposed on the tip concentrically to the axial center is screwed into the screw hole for the screw-fastening, a leading end surface of the screw shaft being pressed against a bottom surface of the screw hole into close contact with each other by the screw-fastening to integrally fix the tip to the body without the leading end of the body abutting on the tip, the body being disposed with a restraining hole concentrically to the axial center.

Abstract: A machining head replaceable rotating tool having a fastening male screw and a fastening female screw disposed on respective shaft centers of one and the other of a machining head and a holder, the fastening male and female screws being threadably engaged with each other to concentrically and removably attach the machining head to a tip portion of the holder, the machining head and the holder being disposed with abutting surfaces abutted against each other in a fastened state when the fastening male and female screws are threadably engaged, the machining head replaceable rotating tool being integrally and rotationally driven via the holder in a tool rotation direction causing the fastening male and female screws to be fastened by a machining load to perform predetermined machining with the machining head, the abutment of the abutting surfaces preventing the fastening male and female screws from being further fastened by a machining load, the fastening male and female screws being saw-tooth buttress screws hav

Abstract: A throw-away rotating tool includes plural protrusions formed in a part of an outer peripheral wall of a projecting coupling portion. Since the twist angle and a twist direction of the protrusions are set in such a way that with relative rotation when coupling the projecting coupling portion and erected portions together, due to the reaction force received by the protrusions from inner peripheral walls, the projecting coupling portion is pulled to the rear and side of the erected portions and the projecting coupling portion is stably held between the erected portions. Since the number of portions that require stringent dimension control and high machining accuracy can be reduced, productivity can be improved.

Abstract: A bevel head replaceable rotary tool is provided. The rotary tool includes a coupling protrusion and a coupling recess, plural sets of serrations provided on an outer circumferential surface of the coupling protrusion and an inner wall surface of the coupling recess, circumferential abutting portions provided on the tool body and the bevel head, and axial tight-contact portions, provided on the tool body and the bevel head. The serrations of the coupling protrusion and the serrations of the coupling recess arranged such that curvatures of circumferential circular arcs of the serrations of the coupling protrusion are greater than those of the serrations of the coupling recess or the serrations of the coupling protrusion and the serrations of the coupling recess have circumferential circular arcs with centers deviated from each other.

Abstract: In a semi-finishing cutter, rectangular tips and square tips are disposed in a staggered pattern in an axial direction in second to fourth step portions, so a single cutting edge is formed by a pair of one of the rectangular tips and one of the square tips. It is therefore possible to effectively reduce a frequency of contact with a blade root. A cutting speed of the semi-finishing cutter may be increased and a cutting feed may be made faster, so work in a semi-finishing process may be performed efficiently. The rectangular tips and the square tips have simple shapes, so known commercially available throwaway tips may be used. Accordingly, it is possible to provide the semi-finishing cutter in an easy-to-use form without increasing the cost.

Abstract: In a rough cutting cutter, square tips and rectangular tips are disposed in a staggered pattern in an axial direction in second to fourth step portions, so a cutting edge is formed by a pair of one of the square tips and one of the rectangular tips. It is therefore possible to effectively reduce a frequency of contact with a blade root. Furthermore, in the second to a fifth step portions, ARs (rake angles in the axial direction) and RRs (rake angles in a radial direction) of the square tips and the rectangular tips gradually increase in order from a tip end to a back end of a tool body. It is therefore possible to suppress chatter vibration during machining and is possible to reduce roughness of a cut surface of a work material.

Abstract: A variable lead end mill has a plurality of peripheral cutting edges with different helix angles, the variable lead end mill having a flute bottom diameter of a plurality of helix flutes making up rake faces of the plurality of the peripheral cutting edges, the flute bottom diameter increasing in an axial direction from a tool tip toward a shank.

Abstract: A removable tip type rotary tool is provided in which a rotation stop key and a key groove each having a triangular shape are disposed on opposing surfaces of a body and a tip concentrically attached to a leading end portion of the body in a removable manner. A pair of side surfaces of the rotation stop key and a pair of side walls of the key groove are brought into surface contact by mounting screw. An angle for each of the pair of the side surfaces and the pair of side walls is between 60 to 100 degrees, a groove bottom of the key groove is rounded with a radius from 1.5 to 2.8 mm, corners of opening edges on both sides of the key groove and corners of both base-end side portions of the rotation stop key are rounded with radiuses, respectively, from 1.5 to 2.8 mm.

Abstract: A throw-away rotating tool improves workability of detaching a throw-away tip and prevents from damaging a body. In the throw-away tool, a convex connection for the throw-away tip has protrusions, each of the protrusion includes a sliding contact portion detachably fitted into the inner peripheral groove recessed in the inner peripheral wall of a body. The protrusion has a first tilt portion continuous to the sliding contact portion. In detaching the throw-away tip from the body, the first tilt portion rotates ahead of the sliding contact portion, and a standing portion is elastically deformed due to a wedge effect of the first tilt portion. As a result, the protrusion can be gently removed from the inner peripheral groove.

Abstract: In cutting processes of a tree-shaped groove, in a rough cutting process, by using a rough cutting tool (20), as well as cutting a tapered groove (2), cutting is performed in a first narrow portion (11), a second narrow portion (12), and a third narrow portion (13) of a planned groove shape 10 such that a specified cutting allowance is left. In the following semi-finishing process, by using a semi-finishing tool, cutting is performed for portions other than the three narrow portions (11 to 13) that have already been cut. Because a work material 1 does not come in contact with three reduced diameter portions, of the semi-finishing tool formed in an upside-down Christmas tree shape, corresponding to the three narrow portions (11 to 13), a load is not imposed on the three reduced diameter portions, which are weak against shock among all portions of the semi-finishing tool, and the cutting feed can therefore be faster. Further, by performing a finishing process, the tree-shaped groove can be efficiently cut.

Abstract: A throw-away rotating tool includes at least two grooved portions 13b, 13c formed on each of erected portions 13 and at least two protrusions 26, 27 for fitting into and removal from respective grooved portions 13b, 13c and projected from a projecting coupling portion 23, and the grooved portions 13b, 13c are formed asymmetrically about an axis O and the protrusions 26, 27 are formed asymmetrically about the axis. Thus, the direction in which the projecting coupling portion 23 can be coupled to the erected portions 13 is uniquely determined. Consequently, variations in lip height and run-out can be minimized. As a result, occurrence of a bend and an increase in machined hole diameter during drilling can be prevented, thereby making it possible to minimize variations in machining accuracy and tool life.

Abstract: A throw-away rotating tool improves workability of detaching a throw-away tip and prevents from damaging a body. In the throw-away tool, a convex connection 23 for the throw-away tip 20 has protrusions 25, each of the protrusion includes a sliding contact portion 25a detachably fitted into the inner peripheral groove recessed in the inner peripheral wall of a body. The protrusion 25 has a first tilt portion 25b continuous to the sliding contact portion 25a. In detaching the throw-away tip 20 from the body, the first tilt portion 25b rotates ahead of the sliding contact portion 25a, and a standing portion is elastically deformed due to a wedge effect of the first tilt portion 25b. As a result, the protrusion 25 can be gently removed from the inner peripheral groove 13b.

Abstract: A bevel head replaceable rotary tool is provided. The rotary tool includes a coupling protrusion and a coupling recess, plural sets of serrations provided on an outer circumferential surface of the coupling protrusion and an inner wall surface of the coupling recess, circumferential abutting portions provided on the tool body and the bevel head, and axial tight-contact portions, provided on the tool body and the bevel head. The serrations of the coupling protrusion and the serrations of the coupling recess arranged such that curvatures of circumferential circular arcs of the serrations of the coupling protrusion are greater than those of the serrations of the coupling recess or the serrations of the coupling protrusion and the serrations of the coupling recess have circumferential circular arcs with centers deviated from each other.

Abstract: A throw-away rotating tool includes plural protrusions 24a formed in a part of an outer peripheral wall 24 of a projecting coupling portion 23. Since the twist angle and a twist direction of the protrusions 24a are set in such a way that with relative rotation when coupling the projecting coupling portion 23 and erected portions 13 together, due to the reaction force received by the protrusions 24a from inner peripheral walls 13a, the projecting coupling portion 23 is pulled to the rear and side of the erected portions 13 and the projecting coupling portion 23 is stably held between the erected portions 13. Since the number of portions that require stringent dimension control and high machining accuracy can be reduced, productivity can be improved.

Abstract: A machining head replaceable rotating tool having a fastening male screw and a fastening female screw disposed on respective shaft centers of one and the other of a machining head and a holder, the fastening male and female screws being threadably engaged with each other to concentrically and removably attach the machining head to a tip portion of the holder, the machining head and the holder being disposed with abutting surfaces abutted against each other in a fastened state when the fastening male and female screws are threadably engaged, the machining head replaceable rotating tool being integrally and rotationally driven via the holder in a tool rotation direction causing the fastening male and female screws to be fastened by a machining load to perform predetermined machining with the machining head, the abutment of the abutting surfaces preventing the fastening male and female screws from being further fastened by a machining load, the fastening male and female screws being saw-tooth buttress screws hav

Abstract: In cutting processes of a tree-shaped groove, in a rough cutting process, by using a rough cutting tool (20), as well as cutting a tapered groove (2), cutting is performed in a first narrow portion (11), a second narrow portion (12), and a third narrow portion (13) of a planned groove shape 10 such that a specified cutting allowance is left. In the following semi-finishing process, by using a semi-finishing tool, cutting is performed for portions other than the three narrow portions (11 to 13) that have already been cut. Because a work material 1 does not come in contact with three reduced diameter portions, of the semi-finishing tool formed in an upside-down Christmas tree shape, corresponding to the three narrow portions (11 to 13), a load is not imposed on the three reduced diameter portions, which are weak against shock among all portions of the semi-finishing tool, and the cutting feed can therefore be faster. Further, by performing a finishing process, the tree-shaped groove can be efficiently cut.

Abstract: In a semi-finishing cutter, rectangular tips and square tips are disposed in a staggered pattern in an axial direction in second to fourth step portions, so a single cutting edge is formed by a pair of one of the rectangular tips tips and one of the square tips. It is therefore possible to effectively reduce a frequency of contact with a blade root. A cutting speed of the semi-finishing cutter may be increased and a cutting feed may be made faster, so work in a semi-finishing process may be performed efficiently. The rectangular tips and the square tips have simple shapes, so known commercially available throwaway tips may be used. Accordingly, it is possible to provide the semi-finishing cutter in an easy-to-use form without increasing the cost.