New Clamping mechanism allows clamping force to be applied not only downward but also pulling inward towards the tool body. Unique feature improves clamping rigidity and position accuracy which in turn would extend insert tooling life. Locating pin on the front of the clamp makes an arc contact with the inner wall of insert hole, resulting an evenly distributed clamping force to be more secure and rigid. Locating lug on the back of the clamp matches with the slot on the tool body to guide the clamp to be seated repetitively which would improve clamping accuracy.