A drill head is rotated about a center axis. The drill head includes: a mounting surface that is an end face in a direction of the center axis; a tip surface that is an opposite surface to the mounting surface in the direction of the center axis; an outer peripheral surface continuous to the mounting surface and the tip surface; a cutting edge extending from the outer peripheral surface toward the center axis in the tip surface; a flute that is formed on the outer peripheral surface and extends spirally around the center axis from the tip surface to the mounting surface; and a thinning surface continuous to the tip surface and the flute. The tip surface includes: a first flank surface continuous to the cutting edge; and a second flank surface located on a side opposite to the first flank surface with the flute interposed therebetween.

A drill structure comprises a shank part and a bit part. A web is formed on the front end of the bit part. Two sides of the web are tilted backward to form two cutting faces. At least one flute (chip-discharge groove) is formed on the surface of the bit part. Each cutting face includes a primary cutting face and a secondary cutting face. The thickness of the prismatic web edge of at least one primary cutting face is smaller than the outer-side width of the primary cutting face. An auxiliary cutting face is extended to the wall of the flute from the cutting edge of the primary cutting face and a portion of a blade back of the secondary cutting face of another cutting face. The present invention decreases the drilling resistance during drilling a hole and increases the service life of the drill bit.

The invention relates to a carbide insert (2) for a rock drill (1), which is configured as a non-percussively operating twist drill with a cylindrical drill body (11) and a working end (13) having the carbide insert (2), the carbide insert (2) having two cutting lips (22) which are radially opposite one another relative to an axis of drill rotation (d) and are arranged at an angle to one another to form a centering tip (21) and with each of which a peripheral conveyor spiral (14) may be associated. To be able to introduce a drilled hole more quickly, easily and simply and with less risk of damage into a workpiece of rock, rock-like material, hard plastics, glass or the like, it is proposed that the cutting lips (22) be configured asymmetrically to one another, wherein at least one of the cutting lips (22) defines over its radial profile, in a central region spaced from its radial ends, a tip (23) projecting in the drilling direction (b).

A method for the laser-based generation of a structure on a rake face of a cutting tool is disclosed, where at least one structure is formed by lines that are generated with a mutual spacing of at most 400 m with a laser beam at least in areas within a predetermined contour on at least one rake face of the cutting tool. A course of the lines forming the structure is oriented with respect to a profile of at least one cutting edge of the at least one rake face.

The negative land includes: a first region in which a space between the upper cutting edge and the lower cutting edge becomes wider toward the outer circumferential surface; and a second region which is continuous to the first region and in which the space becomes wider toward the rotation axis. In a cross section perpendicular to the rotation axis, the rake face includes a return face continuous to the outer circumferential surface, the return face being recessed opposite to a rotation direction of the drill. When a first boundary represents a boundary between the outer circumferential surface and the first region and a second boundary represents a boundary between the first region and the second region, a length of the first boundary is larger than a length of the second boundary in a direction parallel to the rotation axis. The second boundary is continuous to the return face.

A drill bit includes a body having a first end, a second end opposite the first end, and an axis of rotation extending centrally through the body. The drill bit includes a cutting head with a cutting tip on the axis of rotation and a cutting portion. The cutting portion includes first tip surfaces on opposite sides of the axis of rotation and second tip surfaces on opposite sides of the axis of rotation. Each first tip surface extends radially outward from the cutting tip to a corresponding second tip surface. Each second tip surface extends from a corresponding first tip surface to an outer periphery of the body. The first tip surfaces define a first tip angle measured through the axis of rotation that is oblique. The second tip surfaces define a second tip angle measured through the axis of rotation that is smaller than the first tip angle.

A drill is provided with a body having a rod shape configured to rotate about a rotational axis, a cutting edge that is located at a tip portion of the body and extends from an outer periphery of the body toward the rotational axis when viewed from the tip portion, a flank located at the tip portion and disposed along the cutting edge, a covering layer that covers at least the tip portion of the body, and one or more recessed portions disposed on the flank at positions close to the cutting edge.

The invention relates to a rotary tool, in particular a drill (2), which extends along a longitudinal axis (4), having an end face (6); a center (12); at least two main cutting edges (8), each of which extends from the center (12) outwards towards a cutting corner (10); a flute (20) associated with each main cutting edge (8), a flank on the end face (18), associated with each main cutting edge (8); a rake angle () between the respective main cutting edge (8) and the flute (20); a ground face (26) which forms a point thinning (30) in the area of the center (12), extends into a radially outer area and defines the rake angle () in the area of the main cutting edge (8). The rotary tool is characterized in that the rake angle () formed by the ground face (26) is constant along the main cutting edge (8), and the flank (18) of the other main cutting edge (8) is formed by the ground face (26). An advantageous, excellent cutting behavior is thereby achieved along the main cutting edge (8). The invention further relates to a method for manufacturing the rotary tool, which is then especially simple to produce.

A hole saw structure, which is cooperated with a hole saw arbor for performing a perforating operation, includes a cylindrical body and a blade set. The cylindrical body has a central chamber and includes an end surface and a peripheral wall. One end portion of the peripheral wall is connected around a circumference of the end surface, the other end portion of the peripheral wall is outwardly folded and overlapped around the peripheral wall so as to form a folded portion, the folded portion includes a folded end, and an inner diameter of the cylindrical body is smaller than an outer diameter of the folded portion. The blade set is disposed on the folded portion and includes at least two cutting teeth and at least two chip discharging notches.

In an embodiment, a drill has an elongated shape and a rotation axis. The drill includes a drilling portion, a shank portion, and a tapered portion. The shank portion includes a first helical flute and a first cutting edge. The tapered portion is located between the drilling portion and the shank portion. The tapered portion includes a second helical flute, a second cutting edge, a chamfered part, and a connection part. The chamfered part is getting smaller gradually as moving toward the first end side. The connection part has a curved surface and connects the second cutting edge and the drilling portion. A ratio of w/L is 0.0015-0.5 where L is a length of the second cutting edge in a front view of the first end, and w is a width of an outer peripheral end of the chamfered part in a direction parallel to the rotation axis.