A cutter for a wood-chipping apparatus has a drum provided around its periphery with a plurality of blades. Straight-edged blades defining with the cutting edges on rotation of the arbor an inner orbit alternate with comb blades each having a plurality of in-line outer blade regions defining an orbit outside the inner orbit. Inclined intermediate flanks extend from the regions of the outer regions of the cutting edge of the comb blades at an angle of 45* to the outer orbit and cross the inner orbit. The arbor is formed ahead of the comb blades with a diameter that is greater than its diameter elsewhere by a distance equal to the radial spacing between the inner and outer orbits.