A method for producing a replaceable cutting head is described. The replaceable cutting head is manufactured by extruding a blank. During extrusion of the blank, a number of helical coolant channels and a number of helical flutes are simultaneously formed. After extrusion, the flutes have a first angle of twist (D1), and the coolant channels have a second angle of twist (D2). After extrusion, the blank is sintered and then reworked to selectively adjust the first angle of twist (D1) and the pitch of the flutes. The method produces an endless blank that is capable of being parted off to a desired length without any sacrificial allowance, which provides significant material and cost savings as compared to conventional methods.

A method for producing a replaceable cutting head is described. The replaceable cutting head is manufactured by extruding a blank. During extrusion of the blank, a number of helical coolant channels and a number of helical flutes are simultaneously formed. After extrusion, the flutes have a first angle of twist (D1), and the coolant channels have a second angle of twist (D2). After extrusion, the blank is sintered and then reworked to selectively adjust the first angle of twist (D1) and the pitch of the flutes. The method produces an endless blank that is capable of being parted off to a desired length without any sacrificial allowance, which provides significant material and cost savings as compared to conventional methods.

A drill head includes a first attachment surface attached to a holder, a head tip surface opposite to the first attachment surface in an axial direction along the central axis, and a head outer peripheral surface continuous with the first attachment surface and the head tip surface. The head outer peripheral surface is provided with a first flute and a second flute extending helically about the central axis from the head tip surface to reach the first attachment surface. The first flute and the second flute are symmetric with respect to the central axis. Each of the first flute and the second flute has a first end and a second end that face each other with a space between them in a circumferential direction along a circumference centered on the central axis.

A drill has at least one main cutting edge (22) and a helical flute (20) abutting the main cutting edge (22). The surface of the flute (20) has a spiral segment (28) and an edge segment (30) abutting the main cutting edge (22). The roughness of the edge segment (30) is less than the roughness of the spiral segment (28). Furthermore, a method for producing a drill is provided.

A drill has at least one main cutting edge (22) and a helical flute (20) abutting the main cutting edge (22). The surface of the flute (20) has a spiral segment (28) and an edge segment (30) abutting the main cutting edge (22). The roughness of the edge segment (30) is less than the roughness of the spiral segment (28). Furthermore, a method for producing a drill is provided.

The invention relates to a drill comprising a body which extends along a longitudinal axis (L) from a rear side (B) to a front side (F), wherein the body comprises a main cutting edge on the front side (F), wherein the body comprises at least one guide bevel which extends in axial direction (A) and toward the front side (F), wherein, toward the front side (F), the guide bevel has an end section which is tapered. The invention further relates to a method for producing such a drill.

The present invention provides a twist drill. A cone portion is provided at a front end of the operating portion, and an exterior surface of the operating portion is provided with a spiral flute for shunting cutting chips. The exterior surface of the cone portion is provided with a plurality of composite cutting blade groups which are sequentially enlarged in diameter from the front end to the rear end of the cone portion. The cone portion is provided with a top blade on the tip. In use, the top blade is used for positioning, and the cutting process is carried out by the top blade and the composite cutting blade groups.

The present invention provides a twist drill. A cone portion is provided at a front end of the operating portion, and an exterior surface of the operating portion is provided with a spiral flute for shunting cutting chips. The exterior surface of the cone portion is provided with a plurality of composite cutting blade groups which are sequentially enlarged in diameter from the front end to the rear end of the cone portion. The cone portion is provided with a top blade on the tip. In use, the top blade is used for positioning, and the cutting process is carried out by the top blade and the composite cutting blade groups.

A drill bit for chiseling stone includes an impact face at an insertion end of the drill bit, a hollow shank, where a delivery passage is defined within the hollow shank, and a drill head, where the drill head has, at a front end of the drill head, a cutting edge, an intake opening, and an intake passage. The intake passage connects the intake opening to the delivery passage. A cross section of the intake passage increases from the intake opening to the delivery passage.

A drill bit for chiseling stone includes an impact face at an insertion end of the drill bit, a hollow shank, where a delivery passage is defined within the hollow shank, and a drill head, where the drill head has, at a front end of the drill head, a cutting edge, an intake opening, and an intake passage. The intake passage connects the intake opening to the delivery passage. A cross section of the intake passage increases from the intake opening to the delivery passage.