Cutting tool assembly and cutting insert therefor

A cutting tool assembly comprising a cutting insert holder and a cutting insert, the cutting insert holder comprising a clamping portion, at a front portion thereof, connected to a body portion;

• the clamping portion comprising:
• a lower clamping jaw having a lower peripheral surface and an upper surface;
• an upper clamping jaw resiliently connected to the lower clamping jaw, the upper clamping jaw having a lower surface and an upper peripheral surface, the lower surface being provided with two elongated spaced apart substantially parallel grooves;
• a through bore passing through the upper and lower clamping jaws, the through bore being internally threaded in at least one of the upper and lower clamping jaws;
• and
• an insert receiving slot defined between the upper and lower clamping jaws;
• the cutting insert comprising:
• an upper surface provided with two elongated spaced apart substantially parallel ridges;
• a lower surface;
• a peripheral side surface between the upper surface and the lower surface, the peripheral side surface being provided with at least one cutting edge;
• a rake surface associated with the at least one cutting edge;
• and
• a through bore passing through the cutting insert, from the upper surface to the lower surface;
• wherein the cutting insert is retained in the insert receiving slot in a retained position by means of a screw which passes through the through bore in the upper and lower jaws of the insert holder and through the through bore in the cutting insert, and wherein in the retained position at least a portion of the lower surface of the cutting insert abuts at least a portion of the upper surface of the lower clamping jaw and the two elongated ridges in the upper surface of the cutting insert cooperate with the two elongated parallel grooves in the lower surface of the upper clamping jaw.