Abstract: A tool holder has a pocket formed therein into which a cutting insert is mounted by a clamp and fastening means. The cutting insert has a wedge shaped recess which extends from the outside surface of the insert and intersects with the upper surface along a line substantially equidistant from the outside surface. The clamp includes two leg portions, the first leg portion being retained in a recess formed in the tool holder and the second leg portion being inserted in and complementary to the wedge shaped recess of the insert. Initial and secondary restraining forces are exerted on the insert when the clamp is fastened to the tool holder.