Abstract: A cutting tool insert to fit in a holding body for mounting to a rotating machine spindle. The cutting tool insert has multiple faces with one face having several in line cutting edges, one behind the other.A vertical V-groove divides the second cutting edge. The cutting tool insert is symmetrical and is removable, turnable about 180.degree. and replaceable to the holding body.

Abstract: A cutting tool comprising a holder and a removable indexable cutting insert clampingly held on the holder. The holder has a cut-out portion having a concave surface and an insert support and clamping block having a conforming convex surface corresponding to the concave surface of the holder cut-out portion movably held relatively therewith by a differential screw. The insert support and clamping block has a surface supporting the insert and a pin projecting through a mounting aperture in the insert. The cut-out portion has sidewall surfaces engaged by corresponding lateral faces of the insert when the block is driven by action on the differential screw into an insert clamping position. The block has a projecting tang or flange disposed in a corresponding groove in the surface of the cut-out portion, the tang or flange and groove combination acting as a pilot and locator for the insert support and clamping block and as a means of transmitting cutting forces applied upon the cutting insert to the holder.