A minor cutting edge has a first minor cutting edge and a second minor cutting edge that extends inward of the insert in a direction of an insert short side face axial line, as the second minor cutting edge extends from the first minor cutting edge in a direction of an insert major face axial line. A flank face of the second minor cutting edge is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from the second minor cutting edge in the direction of an insert long side face axial line, and is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from a major face adjacent to the flank face in the direction of the insert major face axial line.

A second distance is longer than a first distance and a value obtained by dividing the third distance by the fourth distance is more than or equal to 0.5 and less than or equal to 0.8 when it is assumed that the first distance represents a distance between the cutting edge and the mounting surface in a direction perpendicular to the rake face, the second distance represents a distance between the mounting surface and a boundary portion between the rising portion and the flat portion in the direction perpendicular to the rake face, the third distance represents a distance between the boundary portion and a tip of the cutting edge in a direction parallel to the rake face, and the fourth distance represents a distance between the second discharging opening portion and the tip of the cutting edge in the direction parallel to the rake face.

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 rotary cutting tool is provided which, although it has a simple configuration, allows the arrangement of each cutting edge to be easily adjusted. A first cartridge mounting seat has an upper wall surface opposing an outer side surface of a cartridge and further has a first recessed part into which a protrusion is inserted and which comes into contact, at a bottom thereof, with a leading end of the protrusion. A second cartridge mounting seat has an upper wall surface opposing an outer side surface of a cartridge and further has a second recessed part into which a protrusion is inserted and which comes into contact, at a bottom thereof, with a leading end of the protrusion. A depth of the second recessed part is greater than a depth of the first recessed part. An amount of protrusion P of the protrusion is equal to or greater than the depth of the second recessed part.

In an embodiment, a cutting tool includes a holder that is a columnar body and includes a pocket in which an insert disposed. The pocket includes a first surface in contact with the insert, a second surface, and a projecting portion. The second surface is disposed further forward in a rotational direction of a rotational axis than the first surface, and disposed on a radial inner side of the holder. The projecting portion is disposed closer to a radial outer circumferential side of the holder than the first surface and projects forward in the rotational direction of the rotational axis. The second surface is inclined and comes closer to an outer circumference of the holder as going forward in the rotational direction of the rotational axis, in a front view of a first end.

A cutting tool holder (110) configured for mounting thereon a cutting insert (140). The cutting tool holder comprises a body (112) formed with an insert seat (120) configured receiving therein the cutting insert and a seat bore (135) configured for accommodating therein a fastening member (150). The cutting tool holder also comprises an anchoring element (170) received within the body of the holder, the fastening element being configured for secured engagement with the anchoring element and being free of such engagement with the seat bore.

Provided is a milling cutter including: a tool body to rotate about an axis; and cutting edges at an outer peripheral part of a front end of the tool body, wherein the cutting edges include a flat face machining cutting edge extending along a virtual plane perpendicular to the axis, and a recessed groove machining cutting edge projecting further toward a front end side in the axial direction than the flat face machining cutting edge, and the recessed groove machining cutting edge has a first inclined portion extending toward the front end side in the axial direction toward an outside in a radial direction, a second inclined portion arranged outside the first inclined portion in the radial direction and extending toward a base end side in the axial direction toward the outside in the radial direction, and a tip portion connecting the first and second inclined portions.

The present invention relates to a tool body provided with at least one insert seat. The insert seat includes a bottom wall surface and a side wall surface. The side wall surface includes a first side wall surface and a second side wall surface. The first side wall surface includes at least two surface portions. The first surface portion is a curved surface having a recessed shape recessed toward a base end of the tool body, and the second surface portion is a curved surface having a recessed shape recessed toward the base end of the tool body, with a greater curvature radius than that of the first surface portion, or a flat surface. The two surface portions both come into contact with a cutting insert.

A cutting tool assembly includes a tool body and a tool holder including a longitudinal axis around which the tool holder is configured to spin. The tool holder includes a central portion connected to the tool body comprising a fastener hole perpendicular with the longitudinal axis and configured to receive a securing fastener, wherein the fastener hole is offset from the longitudinal axis. The tool holder further includes an eccentric drive member connected to the cylindrical portion. The tool holder can optionally further include an end alignment cylinder connected to the eccentric drive member.

An insert attachment mechanism (100) detachably attaches a cutting insert (2) to an insert attachment part (21) of a tool body (3). The insert attachment mechanism includes an adjustment member (30) and a wedge member (10). The adjustment member (30) is arranged on an inner side of the cutting inset so as to act on the cutting insert in the insert attachment part. The adjustment member is advanceable and retractable in a direction of the central axis of a screw member (40) by rotating the screw member. The wedge member and the cutting insert are arranged on the outer side of the adjustment member in the insert attachment part and exert a pressing force against the cutting insert and an inner wall surface of the insert attachment part. The wedge member (10) is configured such that the screw member (40) is accessible from the outer side of the wedge member.