A cutting insert for a rotary drill tool and drill tool assembly in which an insert and a support body are coupled axially via a complementary shaped projection extending radially outward from the insert and received with a recess indented at a radially inward facing surface of the support body.

A cutting insert for a rotary drill tool and drill tool assembly in which an insert and a support body are coupled via a plurality of axial support surfaces. The support surfaces include a first declined orientation in the axial direction and a second declined orientation in the circumferential direction, so as to manage and control transmission of loading forces at the region of mounting the insert at the support body.

A drill bit includes a body having a first end, a second end opposite the first end, and an axis of rotation extending centrally though the body from the first end to the second end. The body defining an outer diameter. The drill bit also includes a shank adjacent the second end of the body configured to couple to a tool and a cutting head adjacent the first end. The cutting head includes a plurality of axially stacked, progressively sized steps including a first step and a terminal step positioned between the first step and the first end of the body. The steps increase in diameter from the first step to the terminal step. The terminal step having a diameter that is less than or equal to the outer diameter.

Cutting tool for the rotary machining of workpieces, in particular a twist drill, with a cutting tip which has at least one main cutting edge and at least one free surface (24), wherein a flank face adjoins the main cutting edge radially to the outside, and wherein a flank angle of the flank face increases in a radially outward direction.

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.

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.

According to one implementation, a drill includes the first cutting edges, the second cutting edges and a deflection reducer. The first cutting edges drill a prepared hole to a workpiece. The first cutting edges are formed in a tip side of the drill. The first point angle and each first relief angle of the first cutting edges continuously or intermittently decrease from the tip side toward a rear end side of the drill. The second cutting edges ream the prepared hole. The second cutting edges are formed at positions away in the rear end side from the first cutting edges. The second cutting edges have the second relief angles at a maximum diameter position. The deflection reducer reduces deflection of the second cutting edges. The deflection reducer is formed between the first cutting edges and the second cutting edges. The deflection reducer is inserted into the prepared hole.

A tool blank is substantially cylindrical and includes a front end, a rear end and a central longitudinal axis extending therebetween. At least one vein of a superhard material is formed in the blank at the front end. The vein has a depth in the axial direction and a bottom surface, a first side surface and a second side surface. Each vein has an extension in an inward direction from the periphery of the blank. For each vein, the first side surface forms an inclination angle with respect to the longitudinal axis that varies with the radial distance to the longitudinal axis of the blank over at least a major part of the extension. The inclination angle corresponds to a desired axial rake angle of a drill to be manufactured from the tool blank. A drill manufactured from such tool blank and a method for manufacturing a drill is provided.

The invention relates to a drill tip (2), comprising a center (4), at which a chisel edge (6) is arranged, and comprising a main cutting edge (8), which adjoins the chisel edge (6) and runs outward from the center (4). A rake angle is formed along the chisel edge (6) and the main cutting edge (8). The main cutting edge (8) has an inner portion (10), which adjoins the chisel edge (6) and is arranged within the center (4). The main cutting edge (8) has an outer portion (12), which outwardly adjoins the inner portion (10) and is arranged outside of the center (4). A point thinning (16) is formed on the drill tip (2), which point thinning is curved in such a way that the inner portion (10) runs arcuately from an outer edge of the center (4) toward the chisel edge (6). The invention further relates to a method for producing a drill tip (2) of this type.