A ballscrew thread forming tap including a complete thread portion and a leading portion is to be screwed into a prepared hole provided in a workpiece so as to cause an inner circumferential surface of the prepared hole to be plastically deformed for thereby forming a ballscrew thread corresponding to an external thread provided in the complete thread portion. A screw thread of the external thread has a leading flank and a trailing flank, which are to be positioned on a front side of the trailing flank and on a rear side of the leading flank, respectively, when the ballscrew thread forming tap is screwed into the prepared hole. The screw thread is formed such that, in the leading portion, an indentation depth into the workpiece made by the leading flank is smaller than an indentation depth into the workpiece made by the trailing flank.

A ballscrew thread forming tap including a complete thread portion and a leading portion is to be screwed into a prepared hole provided in a workpiece so as to cause an inner circumferential surface of the prepared hole to be plastically deformed for thereby forming a ballscrew thread corresponding to an external thread provided in the complete thread portion. A screw thread of the external thread has a leading flank and a trailing flank, which are to be positioned on a front side of the trailing flank and on a rear side of the leading flank, respectively, when the ballscrew thread forming tap is screwed into the prepared hole. The screw thread is formed such that, in the leading portion, an indentation depth into the workpiece made by the leading flank is smaller than an indentation depth into the workpiece made by the trailing flank.

A hybrid threading tool defines a longitudinal axis and includes a cutting portion with a plurality of cutting teeth. The plurality of cutting teeth are configured to cut a first threading into a workpiece. The hybrid threading tool also defines a forming portion that is attached to the cutting portion and that is arranged therewith along the longitudinal axis. The forming portion includes a plurality of forming teeth configured to plastically deform the first threading into a second threading for the workpiece.

A hybrid threading tool defines a longitudinal axis and includes a cutting portion with a plurality of cutting teeth. The plurality of cutting teeth are configured to cut a first threading into a workpiece. The hybrid threading tool also defines a forming portion that is attached to the cutting portion and that is arranged therewith along the longitudinal axis. The forming portion includes a plurality of forming teeth configured to plastically deform the first threading into a second threading for the workpiece.

An object is to provide a thread forming tap configured to obtain an inside diameter dimension of a female thread having a targeted processing accuracy more easily than in related art. A thread forming tap (1) is a cold forming tap for forming a female thread by causing plastic deformation of a prepared hole of a workpiece, and includes a male thread portion (3) that protrudes in a thread shape in a radial direction. The male thread portion includes at least one protruding portion (5), which includes a plurality of first thread ridges (51) arranged in an axial direction and that protrude in the radial direction and a first root (52) formed between the first thread ridges adjacent to each other in the axial direction, and at least one adjustment portion (6), which is arranged with the at least one protruding portion in one lead of the male thread portion. A distance from an axial center to a section of the adjustment portion corresponding to the first root in the one lead is longer than a root diameter of the first root and shorter than a ridge diameter of the first thread ridge adjacent to the first root.

An object is to provide a thread forming tap configured to obtain an inside diameter dimension of a female thread having a targeted processing accuracy more easily than in related art. A thread forming tap (1) is a cold forming tap for forming a female thread by causing plastic deformation of a prepared hole of a workpiece, and includes a male thread portion (3) that protrudes in a thread shape in a radial direction. The male thread portion includes at least one protruding portion (5), which includes a plurality of first thread ridges (51) arranged in an axial direction and that protrude in the radial direction and a first root (52) formed between the first thread ridges adjacent to each other in the axial direction, and at least one adjustment portion (6), which is arranged with the at least one protruding portion in one lead of the male thread portion. A distance from an axial center to a section of the adjustment portion corresponding to the first root in the one lead is longer than a root diameter of the first root and shorter than a ridge diameter of the first thread ridge adjacent to the first root.

A thread former for the chipless production of a thread has a plurality of pressing lands, which are each arranged at predefined separation angles (T) along a shaping curve. Each separation angle (T) is smaller than or equal to a predefined maximum separation angle (T.sub.max). For nominal thread former diameters (Da) between 6 mm and 20 mm, the maximum separation angle (T.sub.max) is determined such that the following condition: T.sub.max=sin.sup.−1((a×ND.sup.y+b×ND+c)×2×π); is met for i) 6≤ND<10 where a=−0.0008, b=0.00705, c=0.1325, y=2; ii) 10≤ND<12 where a=1.7924/(2×π), b=0, c=0, y=−0.408; or iii) 12≤ND≤20 where a=0.751/(2×π), b=0, c=0, y=−0.104; wherein T.sub.max is the maximum separation angle and ND is the amount of the nominal thread former diameter (Da) measured in millimeters.

A thread former for the chipless production of a thread has a plurality of pressing lands, which are each arranged at predefined separation angles (T) along a shaping curve. Each separation angle (T) is smaller than or equal to a predefined maximum separation angle (T.sub.max). For nominal thread former diameters (Da) between 6 mm and 20 mm, the maximum separation angle (T.sub.max) is determined such that the following condition: T.sub.max=sin.sup.−1((a×ND.sup.y+b×ND+c)×2×π); is met for i) 6≤ND<10 where a=−0.0008, b=0.00705, c=0.1325, y=2; ii) 10≤ND<12 where a=1.7924/(2×π), b=0, c=0, y=−0.408; or iii) 12≤ND≤20 where a=0.751/(2×π), b=0, c=0, y=−0.104; wherein T.sub.max is the maximum separation angle and ND is the amount of the nominal thread former diameter (Da) measured in millimeters.

A thread forming tap includes a partial thread. The partial thread is provided, in the axis direction view, with a protrusion formed so as to protrude in the radial direction and a clearance section formed so as to have a smaller diameter than the protrusion, and as a result of the foregoing, if a thread forming tap rotates in a state where the inner circumferential surface of a pilot hole and the partial thread come into contact, the protrusion of the partial thread can be caused to engage with the inner circumferential surface of the pilot hole. Due to this configuration, rubbing in a state where the partial thread is pressed against the inner circumferential surface of the pilot hole can be suppressed, and as a result, chipping of the partial thread can be prevented.

A thread forming tap includes a partial thread. The partial thread is provided, in the axis direction view, with a protrusion formed so as to protrude in the radial direction and a clearance section formed so as to have a smaller diameter than the protrusion, and as a result of the foregoing, if a thread forming tap rotates in a state where the inner circumferential surface of a pilot hole and the partial thread come into contact, the protrusion of the partial thread can be caused to engage with the inner circumferential surface of the pilot hole. Due to this configuration, rubbing in a state where the partial thread is pressed against the inner circumferential surface of the pilot hole can be suppressed, and as a result, chipping of the partial thread can be prevented.