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 method for producing a tapped bore in a workpiece with a tap drill bit, which, at its drill bit tip, has a primary cutting edge and a thread profile trailing in a tap drilling direction. The method has a tap drilling stroke, in which the tap drill bit is driven into the workpiece with a tap drilling advance in the tap drilling direction and at a tap drilling rotational speed synchronized therewith, and the tool-primary cutting edge produces a core-hole bore, and the thread profile of the tool bit forms an inner thread at the inner wall of the core-hole bore. In the tap drilling stroke, shavings are produced, which are conveyed in a shavings discharge direction, which is oppositely directed to the tap drilling direction, out from the tapped bore and collide here with thread flanks of the inner thread that face the shavings that are discharged.

The present disclosure provides a variable helical composite tap, which includes a drill bit segment and a tap segment sequentially arranged, where a helical angle of the drill bit segment is greater than a helical angle of the tap segment, and a core thickness of the tap segment is greater than a core thickness of the drill bit segment. The helical angle of the drill bit segment from a drill tip to a connection end of the tap segment with the drill bit segment increases continuously. The helical angle of the tap segment from the drill tip to a drill handle increases continuously, and preferably, the core thickness from the drill tip to the drill handle increases continuously. Compared with the prior arts, the drill bit segment of the present disclosure has a greater helical angle and a better chips removal effect is produced in the drill bit.

A thread cutting drill tool for metal cutting includes a cutting section having an axially extending chip flute and land, and a plurality of axially spaced teeth. Each tooth has an axially forward facing front flank and an axially rearward facing rear flank, a radially outward facing crest connecting the front flank and the rear flank, and a cutting edge. The cutting edge includes a set of crest cutting edges, each crest cutting edge being formed by an intersection of the crest of one tooth with the chip flute. The cutting edges include a set of front finishing edges and a set of rear finishing edges. Each front finishing edge is formed by an intersection of the front flank of one tooth with the chip flute. Each rear finishing edge is formed by an intersection of the rear flank of a tooth with the chip flute.

A multi-sectional drilling and tapping apparatus includes a shank, a drill and a tap that are made in one piece. The shank is formed at an end while the drill is formed at another end. The drill includes a small section formed between a tip and a large section. The drill further includes helical blades extending to the shank from the tip. The tap includes helical ribs each extending from a corresponding one of the helical blades and groups of tooth-shaped blades each evenly arranged along a corresponding one of the helical ribs. The tap includes a diameter larger than that of the large section of the drill.

A thread milling tool extends along an axis of rotation and contains a thread milling section and a drill tip adjoining the thread milling section. The thread milling section has three cutting flutes and at least one thread milling tooth, while the drill tip has three main cutting edges, each of which reaches a main cutting circle when viewed in parallel to the axis of rotation. The main cutting circle defines a drilling diameter that can be produced by the drill tip. Each main cutting edge has a main cutting surface that is connected to one cutting flute of the cutting flutes and reaches the main cutting circle at a respective radial main cutting angle when viewed in parallel to the axis of rotation, and at least one radial main cutting angle of the radial main cutting angles is positive.

In a method for creating a through-thread, thread creation means is moved in a screw-in movement in an axial forward direction (VR) through a workpiece from a first workpiece side to a second workpiece side opposite the first workpiece side such that the end face projects out of the workpiece, wherein the thread creation means is moved through the workpiece, in particular along a first line which is a helical line, wherein then, to create at least one countersink, the thread creation means is moved in a countersinking movement, in particular along a second line that differs from the first line, and wherein, for subsequent withdrawal, the thread creation means is moved back through the workpiece in a screw-out movement in the axial backward direction (RR), in particular at least substantially along the first line.