An indexable, insert for single-point and multiple-point negative rake holding devices which convert the cutting point to a positive cutting geometry. The insert has straight descending and widening V-shaped grooves from each corner along the adjacent sides, each groove modulating into a low angle straight section which rises abruptly into a radial cross-ridge at the midpoint of the groove, the cross-ridge rising to a crest line below the plane of the resulting island created by the grooves around the insert.