Abstract: A metal cutting insert (10) having a pair of cutting portions (10a, 10b) disposed on either end of a shank portion (10c), each cutting portion having a front clearance face (20), the upper boundary of which defines a cutting edge (14). A pair of spaced apart chip breaking surfaces (26a, 26b, 28a, 28b) commence at or near the cutting edge and extend away from the cutting edge. A pair of secondary chip breaking surfaces (44a, 44b, 46a, 46b, 48a, 48b, 50a, 50b) are located downstream of the first chip breaking surfaces and are interconnected with associated first chip breaking surfaces by transition surfaces. A center channel (30) is located between the chip breaking surfaces and includes an entry portion (30a). A tool holder (100) includes a base (102) and clamping arm (104) which together define a gap (106) for receiving one of the cutting portions of the insert.

Abstract: A metal cutting insert having a pair of cutting portions disposed on either side of a shank portion which also includes a clamping structure engageable by a tool holder by which the metal cutting insert is held in an operative position. Each cutting portion includes a circular cutting edge that is defined by the juncture of a circular clearance surface and a frusto-conical, positive rake surface. The cutting edge is located in a common horizontal plane. A plurality of elongate spaced apart, radially directed recesses are symmetrically spaced with respect to the cutting edge and include outer ends that merge with the frusto-conical rake surface and inner ends which merge with a plateau-like surface having an upper surface located at a level higher than the cutting edge. The plateau-like surface defines a discontinuous circular edge in the form of arcuate ridges.

Abstract: A metal cutting insert having a pair of cutting portions disposed on either side of a shank portion. Each cutting portion includes a forward cutting edge and two side cutting edges. Each side cutting edge forms part of a shelf that includes chip controlling/breaking structure and is defined by the juncture of a cutting surface with an upper boundary of a side face. The chip controlling structure includes a chip deflecting surface located adjacent the side cutting surface that includes a plurality of concave recesses that generate localized stiffening of a chip as it moves along the chip deflecting surface. Chip controlling structure located adjacent the forward cutting edge includes a downwardly sloping surface that forms part of a channel which extends from the forward cutting edge towards a shank portion of the insert. A pair of ridges located on either side of the channel rise upwardly and reach a height that is above the plane of the forward cutting edge.

Abstract: A metal cutting insert having a pair of cutting portions disposed on either side of a shank portion which also includes a clamping structure engageable by a tool holder by which the metal cutting insert is held in an operative position. Each cutting portion includes a circular cutting edge that is defined by the juncture of a circular clearance surface and a frusto-conical, positive rake surface. The cutting edge is located in a common horizontal plane. A plurality of elongate spaced apart, radially directed recesses are symmetrically spaced with respect to the cutting edge and include outer ends that merge with the frusto-conical rake surface and inner ends which merge with a plateau-like surface having an upper surface located at a level higher than the cutting edge. The plateau-like surface defines a discontinuous circular edge in the form of arcuate ridges.

Abstract: A metal cutting insert having a pair of cutting portions disposed on either side of a shank portion. Structure is formed on the metal cutting insert by which the insert is clamped to a tool holder which positions one of the cutting portions in a machining position. Each cutting portion includes a forward cutting edge and two side cutting edges. Each side cutting edge forms part of a shelf that includes chip controlling/breaking structure. Each side cutting edge is defined by the juncture of a cutting surface with an upper boundary of a side face and the chip controlling structure includes a chip deflecting surface located adjacent the side cutting surface that includes a plurality of concave recesses that generate localized stiffening of a chip as it moves along the chip deflecting surface. The forward cutting edge performs cutting operations on a rotating workpiece in a radial direction.