A cutting insert includes a cylindrical body portion, a cutting portion, a first fitting portion, a second fitting portion, and a third fitting portion. The cutting portion includes a rake face and a flank face. A ridgeline between the rake face and the flank face constitutes a cutting edge. When viewed in the axial direction, the cutting portion is provided opposite to the third fitting portion relative to the insertion hole. When viewed in the axial direction, a straight line extending through an outer circumferential end of the cutting edge and a center of the insertion hole overlaps with the third fitting portion and is located between the first fitting portion and the second fitting portion. A third central angle is smaller than a first central angle and is smaller than a second central angle.

An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

To provide a cutting insert such that a tool body can sufficiently hold the cutting insert even if one of cutting parts is broken. The cutting insert includes two side surfaces opposed to each other, a fixing hole passing through the centers of the two side surfaces, and an outer circumferential surface that is disposed between the outer circumferential edges of the two side surfaces and are connected to the outer circumferential edges of the two side surfaces. The outer circumferential surface includes four cutting parts, a first outer circumferential surface part that is disposed between the first cutting part and the second cutting part, and a second outer circumferential surface part that is opposed to the first outer circumferential surface part and is disposed between the third cutting part and the fourth cutting part. In a side view of the side surfaces from the axial direction of the fixing hole, the first outer circumferential surface part and the second outer circumferential surface part each have the center recessed toward the fixing hole, and a virtual arc having the same diameter as the diameter of the circumcircle of the cutting insert is in contact with two points on each of the outer circumferential surface parts.

A cutting tool includes a two-way indexable cutting insert clamped in a transversely oriented insert receiving pocket of an insert holder. The insert holder includes a forwardly located insert mounting portion that includes upper and lower jaws which together define the insert receiving pocket having a pocket front opening. The lower jaw includes a pocket lower clamping surface. The upper jaw includes a pocket upper clamping surface which faces mutually towards the pocket lower clamping surface and a pocket stopper surface facing generally towards the pocket front opening. The pocket stopper surface is closer to the pocket lower clamping surface and further from the pocket front opening, than the pocket upper clamping surface. The pocket stopper surface is further from the pocket rear opening than the pocket lower clamping surface.

Disclosed is a multiple machining apparatus for, upon receiving a plastic cylindrical work piece therewithin, performing multiple machining operations thereon. The apparatus comprises a rotary fixture capable of rotation; the rotary fixture comprises a proximal means for snugly holding a proximal portion of the work piece, and a distal means for holding substantially the rest of the portion of the work piece. The apparatus further comprises a movable table comprising a blade holder for holding a plurality of blades, each of which corresponding to a machining operation, the movable table and thereby the blade holder capable movement along X, Y and Z axes. The multiple machining operations are executed as the work piece is rotated and with the blades working against the rotating work piece.

An insert may include a main body. The main body may include a first surface, a second surface, a side surface, a first cutting edge and a through hole. The side surface may be located between the first surface and the second surface. The first cutting edge may be located on at least a part of a ridge line where a first side surface of the side surface intersects with a second side surface adjacent to the first side surface. The through hole may open into the first surface. The main body may further include a first concave part located from the first surface to the side surface. The first concave part may be located away from an imaginary straight line connecting the first cutting edge and a center of the through hole in a front view of the first surface.

A tool adaptor has a front retaining portion and a rear mounting portion, the front retaining portion having a base jaw, a clamping jaw, and an insert receiving pocket located therebetween, and the rear mounting portion having a rear mounting surface and a first fastening bore. A primary slot separates the base jaw from the clamping jaw and communicates with the insert receiving pocket, and a secondary slot transverse to the primary slot separates the clamping jaw from the rear mounting portion. The first fastening bore has a first bore axis which intersects the rear mounting surface and the secondary slot. A cutting tool assembly includes a tool shank, and the tool adaptor secured to a front mounting portion of the tool shank by means of a first fastening screw occupying the first fastening bore and a first shank bore of the front mounting portion.

A cutting tool may include a main body having a bar shape extended along a central axis. The main body may include a cutting edge, a first flow path, a second flow path, a third flow and a fourth flow path. The first flow path is located along the central axis and may include an inflow port. The second flow path is located along the central axis and may include a smaller inner diameter than the first flow path. The third flow path may connect to the first flow path and may include a first outflow port. The fourth flow path may connect to the second flow path and may include a second outflow port. The first outflow port is located more away from an imaginary plane including the central axis and the cutting edge than the second outflow port.

An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

A tool adaptor has a front retaining portion and a rear mounting portion, the front retaining portion having a base jaw, a clamping jaw, and an insert receiving pocket located therebetween, and the rear mounting portion having a rear mounting surface and a first fastening bore. A primary slot separates the base jaw from the clamping jaw and communicates with the insert receiving pocket, and a secondary slot transverse to the primary slot separates the clamping jaw from the rear mounting portion. The first fastening bore has a first bore axis which intersects the rear mounting surface and the secondary slot. A cutting tool assembly includes a tool shank, and the tool adaptor secured to a front mounting portion of the tool shank by means of a first fastening screw occupying the first fastening bore and a first shank bore of the front mounting portion.