A tool for producing an internal thread in a workpiece pilot hole having a thread major diameter and a thread minor diameter, which tool has a thread-forming section, by which an internal thread profile can be produced in a pilot hole wall. The internal thread profile having the thread major diameter and a thread inner diameter. The tool has a drilling section, by which the thread inner diameter of the internal thread profile can be expanded to the thread minor diameter by machining. At least one, in particular exactly one chip groove is associated with the drilling section of the tool, by which chip groove the chips produced as the thread inner diameter is expanded to the thread minor diameter can be transported away.

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 thread-rolling flat die for a threaded fastener, includes a thread-rolling surface including at least a bite surface to which a workpiece of the threaded fastener is supplied, a finishing surface formed adjacent to the bite surface, and a roll-off surface formed adjacent to the finishing surface. The bite surface includes at least: a first partial bite surface having an inclination and a second partial bite surface formed continuously from the first partial bite surface and having an inclination. A length L1 along a thread-rolling direction in the first partial bite surface, a length L3 along the thread-rolling direction in the finishing surface, a length L4 along the thread-rolling direction in the roll-off surface, and a diameter of a processed portion of the workpiece of the threaded fastener have a relationship of L1>L3>L4> the diameter of the processed portion.

In a part having a surface, a bolt hole is provided extending into the part from the surface. Threads in the hole have crests with a fishmouth shape at the crests defined by a central concave portion and raised corner portions at ends of the concave portion. At least one start thread preceding the threads with the fishmouth shape crests is provided having a substantially flat crest without the fishmouth shape. A tap for manufacturing the threaded bolt hole has a first thread section and a second thread section. The second thread section has a plurality of threads for creating at least one improved start thread in the hole to be threaded, minor diameters at valleys between the threads of the second thread section being greater than minor diameters at valleys between threads of the first thread section or major diameters at crests of the threads of the second thread section being greater than major diameters at crests of the first thread section.

In a part having a surface, a bolt hole is provided extending into the part from the surface. Threads in the hole have crests with a fishmouth shape at the crests defined by a central concave portion and raised corner portions at ends of the concave portion. At least one start thread preceding the threads with the fishmouth shape crests is provided having a substantially flat crest without the fishmouth shape. A tap for manufacturing the threaded bolt hole has a first thread section and a second thread section. The second thread section has a plurality of threads for creating at least one improved start thread in the hole to be threaded, minor diameters at valleys between the threads of the second thread section being greater than minor diameters at valleys between threads of the first thread section or major diameters at crests of the threads of the second thread section being greater than major diameters at crests of the first thread section.

A thread former includes a shank and a forming section having a polygonal cross-section. A ridge or a plurality of ridges of the thread former extend along the circumference of the forming section that has at least two axially adjacent ridges and/or interruptions. In order to provide a thread former in which the wear is further reduced and the machining speed or the number of manufactured tapped holes can be further increased without increasing the wear or even with the reduction of wear, there is suggested that on axially adjacent ridge sections at least some of the interruptions are arranged at different angular positions.

The present invention relates to a threading tool for producing a thread notch on a workpiece. The production may be both material-removing production and also chipless production. The threading tool comprises at least two regions, a distal machining region with a machining head, and a proximal shank region with a shank, which shank narrows toward the machining region via a shoulder. Furthermore, the threading tool according to the invention is designed such that at least one fluid duct extends through the shank, which at least one fluid duct opens out in the machining region.

The invention relates to a thread forming tool having a thread part based on a helical effective surface (1), and an adjoining clamping shank (2), wherein the helical effective surface (1) is formed by pressing lobes (5) and the thread part extends from a chamfer or taper (6) in the direction of the clamping shank (2). Furthermore, at least one axially oriented, groove-like cooling channel (7) that runs between the pressing lobes (5) and extends from the chamfer or taper (6) to the clamping shank (2) is provided. According to the invention, the width of the at least one cooling channel (7) increases from the chamfer (6) in the direction of the clamping shank (2).

The invention relates to a thread forming tool having a thread part based on a helical effective surface (1), and an adjoining clamping shank (2), wherein the helical effective surface (1) is formed by pressing lobes (5) and the thread part extends from a chamfer or taper (6) in the direction of the clamping shank (2). Furthermore, at least one axially oriented, groove-like cooling channel (7) that runs between the pressing lobes (5) and extends from the chamfer or taper (6) to the clamping shank (2) is provided. According to the invention, the width of the at least one cooling channel (7) increases from the chamfer (6) in the direction of the clamping shank (2).