A device for the precise angular positioning of tool-holders includes a front part, a rear part, and a plug cooperating with a pair of pins arranged orthogonally relative to the plug. A first portion of the plug is inserted in a blind hole formed in the front part and a second portion of the plug is inserted in a corresponding blind hole formed in a front area defining a plate on the rear part of the tool-holder. The plate of the rear part has an upper surface in which a pair of bored holes is formed having equal diameters and depths. The bored holes extend vertically in the plate and orthogonally relative to the plug. A pin is rotatably inserted in each of the pair of bored holes to selectively rotate the plug in a clockwise or counter-clockwise direction to orientate the front part relative to the rear part.

A cutting insert has a cutting portion corner formed at the intersection of a rake surface, a forward cutting portion surface and a relief surface. A cutting edge is formed at an intersection of the rake surface and the relief surface with a land that is located on the rake surface and that extends along, and negatively away from, the cutting edge. A chip-control arrangement is located at the rake surface and includes an elongated projection and plurality of spaced apart elongated protuberances that extend from the projection to the cutting edge, so that the land has a plurality of spaced apart bulging land portions. A non-rotary cutting tool has an insert holder having an insert pocket and the cutting insert releasably retained therein.

An insert adaptor for parting off including an adaptor index axis and parallel adaptor first and second sides connected by an adaptor peripheral surface which extends peripherally around the adaptor. The adaptor peripheral surface is formed with at least three pockets and bearing surfaces extending between the pockets. Each of the pockets comprises resilient upper and lower clamp surfaces.

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.

A turning tool adaptor includes opposite first and second side surfaces and a peripheral surface which extends therebetween. The turning tool adaptor further includes a cutting portion with an insert retaining portion and a clamping portion which extends from the cutting portion. The clamping portion includes a protrusion which extends transversely from the first side surface. The protrusion includes a main abutment surface and spaced apart first and second adaptor clamping bores which open out to the second side surface and also to the main abutment surface. The turning tool adaptor has first, second and third abutment surfaces which are located between the top and bottom surfaces in a side view perpendicular to one of the side surfaces.

A cutting insert (112) comprising a top surface (118), a bottom surface (120), and side surfaces (122) spanning there-between, said side surfaces (122) comprising one or more feed-facing side surfaces (122a) and one or more radial-facing side surfaces (122b). The top surface (118) is formed with one or more linear grooves, each constituting a chip breaker (125) and being disposed parallel to and adjacent one of said feed-facing side surfaces (122a). The chip breaker (125) is characterised by a constant profile along the entire length of its respective feed-facing surface (122a). Each of said feed-facing side surfaces (122a) is disposed at an acute feed-angle ( feed) with respect to the top surface (118), and each of said radial-facing side surfaces (122b) being disposed at an acute radial-angle ( radial) with respect to the top surface (118), the feed-angle ( feed) being greater than said radial-angle ( radial).

Cutting tool holders are disclosed that include vibration dampening elements. The vibration dampening elements may extend parallel to a longitudinal plane of the cutting tool holder. The vibration dampening elements allow the cutting tool holders to have a smaller width while still providing higher grooving depth.

A device for the controlled stabilization of tool holder shanks on the respective ring nut, the tool holder shanks, motorized or non-motorized, being predisposed for ER or other type fixing. The device comprises a ring nut and a tool holder shank of a truncated conical shape provided externally with a groove in which means connecting the ring nut to the tool holder are arranged inside the ring nut. The connecting means consist of an annular body formed of at least two shaped half-rings that define opposite protrusions projecting outwardly and centrally to form a shaped prominence having an arched-convex outer profile; on each of the shaped prominences a recess is made predisposed to house respective elastic pins, by means of which the shaped half-rings are firmly connected inside the ring nut blind holes.

A cutting tool for performing cutting of a relatively rotating external workpiece while relatively feeding the same in a specified direction is configured to have: cutting sections that have a tool edge, a base section, which is provided as one piece with or separate from the cutting sections and is for holding the cutting sections, a chip-guiding wall, which starts near a tool edge, is formed on the outer circumferential surface of the base section so as to extend in the direction moving away from the tool edge, and is for interfering with chips from the external workpiece and guiding the chips in a direction away from the tool edge. Provided thereby is a cutting tool capable of smoothly discharging chips during cutting.

A cutting tool for performing cutting of a relatively rotating external workpiece while relatively feeding the same in a specified direction is configured to have: cutting sections that have a tool edge, a base section, which is provided as one piece with or separate from the cutting sections and is for holding the cutting sections, a chip-guiding wall, which starts near a tool edge, is formed on the outer circumferential surface of the base section so as to extend in the direction moving away from the tool edge, and is for interfering with chips from the external workpiece and guiding the chips in a direction away from the tool edge. Provided thereby is a cutting tool capable of smoothly discharging chips during cutting.