Abstract: The indexable insert possesses two parallel cutting edges on opposite sides of an indexable insert body in the form of a rectangular block. In the intermediately placed top surface descending toward the center line (M) there is a chipbreaking structure comprising alternating projections and recesses. These projections and recesses constitute a row, centered on the center line (M), of spherical-like chipbreaking bodies, between which concave chip guiding surfaces are formed. During metalcutting operations, this provides an even flow of chips with the formation of short chips which are free of grooves and tears along the edges.

Abstract: A cutting tool assembly with a clamping mechanism for releasably clamping a tool bit (18) on a tool holder (10) is disclosed. The tool holder (10) defines an elongated planar seating surface (12) with a socket (14) on its forward end and a threaded bore (20) on its rear end. A further threaded bore (22) is provided in the seating surface intermediate the forward and rearward ends. A conical tool bit (18) forms a circular cutting edge (52) and has a shank (16) adapted to be received in the socket (14). An elongated bar-shaped clamping member (32) has one end engaging in a circumferential groove (28) of the tool bit (18). The opposite end of the clamping member (32) has arcuate concave surface portion (32b) for abutment with the conical surface on a tapered head (34) of an adjustment screw (36) engaged in the threaded bore (20) of the seating surface (12).