Abstract: An improved chipper knife system includes reversible chipper knives having formed integrally thereon nose structures comprising a leading component of a chip breaking system. A clamp plate surface follows the nose structure and, by virtue of the nose structure taking wear, has extended life and, therefore, extended value. A simple clamp arrangement includes knife registration relative to a clamp plate and a calibration keeper bar establishes a fixed position between the clamp plate the knife holder. Knives are thereby dismounted and remounted relative to the clamp without an intermediate calibration step.