A 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 an internal thread corresponding to the 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 thread forming tap is screwed into the prepared hole. The screw thread is shaped 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 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 an internal thread corresponding to the 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 thread forming tap is screwed into the prepared hole. The screw thread is shaped 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 method of manufacturing a threaded hole in a workpiece includes providing the workpiece having a region with a hole. The method also includes cutting a threading for the hole. Furthermore, the method includes, independent of cutting the threading, densifying the region proximate the hole to reduce material porosity in the region.

A thread tap includes a shaft and teeth. The shaft includes helical passages from the threading end to the base end of the shaft. Each passage opens through an aperture in the threading end. A second tap includes a cap and the shaft includes an axially extending passage. The cap is coupled to the threading end and at least partially defines apertures in fluid communication with the passage and the exterior of the tap. A third tap includes teeth spaced apart by a plurality of linear flutes. The shaft includes a central passage and a plurality of flute passages. Each flute passage extends radially outward from a common location in the central passage to a corresponding one of the flutes. The central passage is closed to a terminal end of the threading end.

A tool for the chipless production of a thread in a workpiece comprises at least one shaping region which can be rotated about a tool axis (A) for the chipless production or finishing of the thread. The shaping region comprises a plurality of pressing lobes projecting radially outwardly from the tool axis (A) for producing the thread by pressing the pressing lobes into the workpiece surface. The pressing lobes are successively arranged along a forming curve which substantially spirals around the tool axis (A), and the pitch of the forming curve essentially corresponds to the pitch of the thread to be produced or reworked. The forming curve has a helix angle (a), and a profile of at least one pressing lobe is designed in such a way that a thread produced in an axial section containing the tool axis is at least in sections round-arched or ogival.

A tool for the chipless production of a thread in a workpiece comprises at least one shaping region which can be rotated about a tool axis (A) for the chipless production or finishing of the thread. The shaping region comprises a plurality of pressing lobes projecting radially outwardly from the tool axis (A) for producing the thread by pressing the pressing lobes into the workpiece surface. The pressing lobes are successively arranged along a forming curve which substantially spirals around the tool axis (A), and the pitch of the forming curve essentially corresponds to the pitch of the thread to be produced or reworked. The forming curve has a helix angle (a), and a profile of at least one pressing lobe is designed in such a way that a thread produced in an axial section containing the tool axis is at least in sections round-arched or ogival.

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 thread forming tap includes a screw thread formed into a male thread shape with margin portions disposed to project in radial direction and relief portions having a diameter smaller than the margin portions, the margin portions and relief portions alternatively arranged and, thread forming tap causes the margin portions of the screw thread to cut into a surface layer portion of a prepared hole formed in a work to plastically deform the surface layer portion to form a female thread, margin portions are formed into a ridge line shape with a width dimension of zero at least at a thread bottom of the screw thread, and margin portions are formed into a ridge line shape with a width dimension of zero in a range from a thread bottom of the screw thread to a position between the thread bottom and an effective diameter position of the screw thread.

A thread forming tap includes a screw thread formed into a male thread shape with margin portions disposed to project in radial direction and relief portions having a diameter smaller than the margin portions, the margin portions and relief portions alternatively arranged and, thread forming tap causes the margin portions of the screw thread to cut into a surface layer portion of a prepared hole formed in a work to plastically deform the surface layer portion to form a female thread, margin portions are formed into a ridge line shape with a width dimension of zero at least at a thread bottom of the screw thread, and margin portions are formed into a ridge line shape with a width dimension of zero in a range from a thread bottom of the screw thread to a position between the thread bottom and an effective diameter position of the screw thread.