the invention relates to a rotary cutter for the pelletization of plastic extrudates , said rotary cutter being provided with knives projecting axially away from its end surface , said knives being individually affixed to supporting surfaces of the rotary cutter by means of fastening elements . the supporting surfaces are formed by the side walls of radial grooves in the peripheral surface of the rotary cutter and by radial transverse walls in the radial grooves , said radial grooves being limited by the radial transverse walls , the knives each being inserted in hook - like manner with a projecting portion into said radial transverse walls , wherein one side of the projecting portion forms an abutment for the fastening element , said fastening element penetrating a radial transverse wall and pressing on the abutment .