The invention relates to a single-lip drill and a double-lip drill having a plurality of chip-forming devices or depressions in the rake face which are arranged in succession and at a distance from one another. As soon as a cutting edge and/or the associated chip-forming device or the associated depression is worn, the deep hole drill according to the invention can be reground using simple means.

A single-edge drill for forming a deep hole is provided which includes a body and a shank. The body has a single chip discharge groove in the outer periphery thereof, and includes a small-diameter portion, and a large-diameter portion having coolant delivery grooves in the outer periphery thereof. The body has a core thickness at the distal end portion of the large-diameter portion. At the other portion of the body, the groove bottom of the chip discharge groove is located beyond the rotation center of the drill such that the body has no core thickness, and when taken perpendicularly to the axial direction of the drill, the cross section of the body has a crescent shape. When a hole is formed with the drill, a supply path for coolant liquid is defined between the outer peripheral surface of the small-diameter portion and the radially inner surface of the hole.

A drilling tool with improved structure to improve chips discharging performance. The drilling tool comprises a cutting insert 60 having a cutting edge 62 at the front end portion and a main body 10 mounted with the cutting insert 60, further, the drilling tool comprises a hollow discharge channel 12 formed inside the main body 10, and the discharge channel 12 has a curved surface 14 for guiding the chips S in a direction towards the base end portion opposite to the front end portion.

A drilling system and methods provide stability and cutting performance to produce holes having desired straightness and other characteristics. The system may include a cutting head provided with a central cutting system and first and second side cutting inserts. The tool provides a major diameter with the OD cutting margins on the replaceable side inserts, as well as possibly cutting margins on the center cutting member. Adjustment mechanisms may be provided to adjust the center cutting member and/side cutting inserts.

The invention relates to a four-edged drill having two long main cutting edges, arranged in a point-symmetric manner with regard to the axis of rotation, which each extend from an outer circumferential cutting corner to a chisel edge in the middle of the drill tip, and two short main cutting edges, arranged in a point-symmetric manner with regard to the axis of rotation, which each extend from an outer circumferential cutting corner in the direction of the middle of the drill tip. According to the invention, each long main cutting edge has an outer partial cutting edge, extending from the cutting corner as far as a shoulder, and an inner partial cutting edge, extending from the shoulder as far as the chisel edge, said inner partial cutting edge having a greater cutting height (x) than the outer partial cutting edge and the short main cutting edges.

A drill is a long drill that is provided with a discharge groove having a helix angle of 25 degrees, in which a groove length is 30D or more. Thinning processing is performed on a leading end portion of the drill and a gash portion that is connected to the discharge groove further to an inner side in the radial direction than an outer peripheral surface. A circular arc groove is formed in a section connecting a thinning face and a gash face, and a chip discharge performance is improved. When forming a deep hole, in a guide hole forming process, a guide hole with an inner diameter d of D+0.03 mm or less and with a depth W of 3D or more, is formed (S2 to S6). In an insertion process, the drill is rotated in a reverse direction and is inserted into the guide hole to a position just before a bottom portion of the guide hole (S11 to S13). In a deep hole forming process, the drill is rotated in a positive direction, cutting is performed from the bottom portion of the guide hole, and a deep hole is formed (S16 to S18).

A deep hole drilling system and methods provide stability and cutting performance to produce deep holes having desired straightness. The system may include a replaceable cutting head provided with a center cutting member and first and second side cutting inserts. The tool provides a major diameter with the OD cutting margins on the replaceable side inserts, as well as possibly cutting margins on the center cutting member. Adjustment mechanisms are provided to adjust the center cutting member and/side cutting inserts.

Described are a drilling tool and a replaceable cutting disk which allow the replaceable cutting disk to be positioned with high accuracy and in a form-locking manner in the drilling tool. At the same time, a cutting disk can be replaced more easily.

A tip that is capable of preventing chip clogging during machining, and a cutting tool equipped with this tip, are provided. The tip 30 includes a first surface 310 that is a portion making contact with a body 20 of the cutting tool 10 when the tip is attached to the body 20, a second surface 320 located on the opposite side from the first surface 310, a leading end part 330 connecting the first surface 310 and the second surface 320 and provided with a cutting edge 331, and a trailing end part 340 located on the opposite side from the leading end part 330. The second surface 320 is formed with a recessed part 321 receding toward the first surface 310 in a portion closer to the trailing end part 340.

The invention relates to a single-lip drill and a double-lip drill having a plurality of chip-forming devices or depressions in the rake face which are arranged in succession and at a distance from one another. As soon as a cutting edge and/or the associated chip-forming device or the associated depression is worn, the deep hole drill according to the invention can be reground using simple means.