Insert retention apparatus

A support member for a cut-off tool insert comprising a generally rectangular blade having a relatively narrow thickness compared to its length and width, such that the thickness is at least as narrow as a cutting edge length of the cut-off tool insert, a front edge of the blade having a relieved segment, an insert locating slot opening at the relieved segment and extending generally rearwardly and downwardly from the relieved segment, the slot having a longitudinal axis substantially normal to the relieved segment, the slot further having upper, lower and rear surfaces shaped for receipt of substantially mating surfaces of the cut-off tool insert having a cutting edge extending normal to side surfaces of the support blade and in front of the relieved segment, a slit having opposing upper and lower surfaces extending from an open end in a top edge of the support blade generally downward and towards the front edge of the support blade at an angle in the order of 30 degrees with a longitudinal axis of the support blade, an opening comprising a substantially circular hole running from one side surface of the blade to the other, positioned below the lower surface of the slit and subtended in chord-like fashion by the lower surface of the slit, a camming member having substantially the same thickness as the blade and shaped for substantially permanent mating location in the opening with a flatted surface located such that the camming member rests in the opening in a non-force-transmitting rotative position with the flatted surface located in and substantially parallel to the slit, the camming member operative upon rotation in either direction from its non-force-transmitting position to bear against the upper surface of the slit to force oppositely facing portions of the upper and lower surface of the insert locating slot toward one another thereby clamping the cut-off tool insert in operative position.