A milling cutting insert has a substantially triangular shape. The cutting insert contains a top side, an underside, and circumferential side surfaces extending between the top side and the underside. Cutting edges are formed at the transition of the circumferential side surfaces to the top side and/or the underside. On the circumferential side surfaces at least two discrete planar abutment surfaces are formed for positioning the cutting insert in a tool holder. The at least two discrete planar abutment surfaces are inclined with respect to each other at an outer angle of between 190 and 220 and the abutment surfaces are spaced from each other with respect to the circumferential direction of the cutting insert.

A milling cutting insert has a substantially triangular shape. The cutting insert contains a top side, an underside, and circumferential side surfaces extending between the top side and the underside. Cutting edges are formed at the transition of the circumferential side surfaces to the top side and/or the underside. On the circumferential side surfaces at least two discrete planar abutment surfaces are formed for positioning the cutting insert in a tool holder. The at least two discrete planar abutment surfaces are inclined with respect to each other at an outer angle of between 190 and 220 and the abutment surfaces are spaced from each other with respect to the circumferential direction of the cutting insert.

In an embodiment, a cutting tool includes a holder and a cutting insert. The holder is elongated, extends from a first end to a second end along a rotational axis. The holder includes an insert pocket on a side of the first end. The cutting insert is located in the insert pocket and includes a cutting edge. The insert pocket includes an opening in an end surface of the first end and an outer peripheral surface adjacent to the first end of the holder. The cutting insert further includes a first portion that is located more radially inward than an outer peripheral opening of in the insert pocket in a front view of the first end of the holder. The first portion has a width greater than a width of the opening in a direction along a rotation direction of the rotation axis.

A single-sided four-way indexable cutting insert includes a positive basic shape, a rake surface, a peripheral surface including four side abutment surfaces, a base bearing surface and a screw hole connecting the rake and base bearing surfaces. The insert has an imaginary square frustum which defines a square base containing the cutting insert's base bearing surface, and further defines four isosceles trapezoid side surfaces respectively containing the cutting insert's four side abutment surfaces. A material volume V.sub.F of the cutting insert and a void volume V.sub.S of the insert fulfill the condition V.sub.S/V.sub.F0.25.

A single-sided four-way indexable cutting insert includes a positive basic shape, a rake surface, a peripheral surface including four side abutment surfaces, a base bearing surface and a screw hole connecting the rake and base bearing surfaces. The insert has an imaginary square frustum which defines a square base containing the cutting insert's base bearing surface, and further defines four isosceles trapezoid side surfaces respectively containing the cutting insert's four side abutment surfaces. A material volume V.sub.F of the cutting insert and a void volume V.sub.S of the insert fulfill the condition V.sub.S/V.sub.F0.25.

A cutter head (4, 6) having a lock spring (30) utilized with an adjustment screw (16) for preventing the adjustment screw from loosening during machining. Once positioned by turning the adjustment screw, a cutting blade (8) will not change position in a mounting slot (10) due to a loosening adjustment screw.

A deburring tool (7) for deburring of edges of transverse recesses (3, 3a-i), which diverge from a main borehole (2), consisting of a shaft (8, 9) driven to turn about the tool axis (11), which is deployable and retractable in the forward feed direction into the main borehole, and on the lower end of which at least one knife window (26) is arranged, in which at least one spring-loaded knife (10, 10, 10, 10, 10) is arranged roughly perpendicular to the tool axis (11), so as to be shiftable, which on its front end has at least one cutting edge (10a, 10b) which encounters the edge of the transverse recess (3, 3a-i), and deburrs same, wherein the knife (10, 10, 10, 10, 10) consists of two cutting edges (10a, 10b) opposite in the rotational direction (12, 13), which act to cut equally for the right and left passes (12, 13), with one cutting edge (10a) being configured to cut for the rightward pass (12), both in forward motion (38a) and in rearward motion, and the other cutting edge (10b), being configured to cut for the leftward pass (13), both in forward motion (38a) and in rearward motion, and that the two cutters (10a, 10b) with their cutting edges are placed at a slant and with arch shape at an angle between 0 and 90, but preferably between 5 and 45 to the tool axis (11) and thus to the longitudinal axis (2a) of the main borehole (2).

A deburring tool (7) for deburring of edges of transverse recesses (3, 3a-i), which diverge from a main borehole (2), consisting of a shaft (8, 9) driven to turn about the tool axis (11), which is deployable and retractable in the forward feed direction into the main borehole, and on the lower end of which at least one knife window (26) is arranged, in which at least one spring-loaded knife (10, 10, 10, 10, 10) is arranged roughly perpendicular to the tool axis (11), so as to be shiftable, which on its front end has at least one cutting edge (10a, 10b) which encounters the edge of the transverse recess (3, 3a-i), and deburrs same, wherein the knife (10, 10, 10, 10, 10) consists of two cutting edges (10a, 10b) opposite in the rotational direction (12, 13), which act to cut equally for the right and left passes (12, 13), with one cutting edge (10a) being configured to cut for the rightward pass (12), both in forward motion (38a) and in rearward motion, and the other cutting edge (10b), being configured to cut for the leftward pass (13), both in forward motion (38a) and in rearward motion, and that the two cutters (10a, 10b) with their cutting edges are placed at a slant and with arch shape at an angle between 0 and 90, but preferably between 5 and 45 to the tool axis (11) and thus to the longitudinal axis (2a) of the main borehole (2).

A cutting insert which is suitable for high cutting speed, a tool body thereof and a tool are provided. A tool according to the present invention is a tool in which a leading end thereof is provided with a force transmitting portion and for which a rotational axis extending from the leading end to a base end thereof is defined, wherein the tool comprises a cam portion which is arranged closer to the base end than the force transmitting portion and for which a dimension from the rotational axis of the tool varies in accordance with an angle at which the cam portion is rotated around the rotational axis.

A cutting insert which is suitable for high cutting speed, a tool body thereof and a tool are provided. A tool according to the present invention is a tool in which a leading end thereof is provided with a force transmitting portion and for which a rotational axis extending from the leading end to a base end thereof is defined, wherein the tool comprises a cam portion which is arranged closer to the base end than the force transmitting portion and for which a dimension from the rotational axis of the tool varies in accordance with an angle at which the cam portion is rotated around the rotational axis.