A drill bit for a drill includes at least one flute having a rake face including a flute edge and at least one cutting edge having a profile that extends along at least a portion of a length of the cutting edge, the rake face extending from the cutting edge. A chip breaker formed in the rake face, the chip breaker being a continuous groove located adjacent the cutting edge, the groove having a starting end and an exit end opening into the flute edge, the starting end having a depth that is less than a depth of the exit end of the groove, wherein a shape of the groove at the starting end is different from a shape of the groove at the exit end.

A drill bit has a shank, an intermediate shaft, and a cutting head and defines a longitudinal axis. The cutting head has a body having a front end, a rear end, and a peripheral sidewall, a primary cutting insert and a pair of auxiliary cutting inserts. The primary cutting insert is cross-shaped with a central portion with a cutting tip and four cutting arms each with a cutting edge extending radially outward from the central portion past the peripheral sidewall. The auxiliary cutting inserts are spaced radially outward from the central portion and circumferentially from the radial cutting arms, and have a cutting edge extending radially outward past the peripheral sidewall. A pair of primary dust egress slots and a pair of auxiliary dust egress slots are formed in the peripheral sidewall and configured to channel debris from the front end to the rear end of the body.

The invention relates to a single-lip deep hole drill comprising a drill head, wherein the drill head has a drill diameter, a blade and a channel for chip removal, wherein the blade extends outwards from a rotational axis (23) up to the perimeter of the drill head, wherein the blade has a cutting surface (33) and wherein the channel is bordered by a chip forming surface (15), wherein the chip forming surface (15) has two sections (19, 21) such that a first section (19) of the chip forming surface (15) extends in the radial direction from the rotational axis (23) up to a first diameter, a second section (21) of the chip forming surface (15) connects to the first section (19) in the radial direction, the first section (19) is positioned above the cutting surface (33), and the second section (21) is positioned nearer to the cutting surface (33) than the first section (19). (H1>0; H1>H2)

A drill bit for a drill includes at least one flute having a rake face including a flute edge and at least one cutting edge having a profile that extends along at least a portion of a length of the cutting edge, the rake face extending from the cutting edge. A chip breaker formed in the rake face, the chip breaker being a continuous groove located adjacent the cutting edge, the groove having a starting end and an exit end opening into the flute edge, the starting end having a depth that is less than a depth of the exit end of the groove, wherein a shape of the groove at the starting end is different from a shape of the groove at the exit end.

A drill includes a substantially cylindrical cutting portion includes a first region located at a front end portion, and a second region which has a step whose diameter increases as going from the first region to a rear end in a sectional view perpendicular to a rotation axis, and which is continuous with the first region in an end of the second region on a side of the step, and using this drill, a method of manufacturing a machined product is provided.