A hand-held tool for making grafting-flap cuts in the bark of a tree limb includes an elongated tubular body having an open end for accommodating coaxial insertion of the limb. The end of the body adjacent the open end has a plurality of elongated slots longitudinally disposed in the tubular body. A plug within the tubular body limits the insertion depth of the limb to a preselected distance. A plurality of elongated knife members are provided. The longitudinal axis of each of the knife members registers with the longitudinal axis of one of the circumferentially spaced slots in said tubular body. The knife members are supported by a support ring radially projecting above the outer surface of the tubular body and are disposed in a corresponding plurality of radially projecting circumferentially equally-spaced slots in the support ring. An elastic band is coaxially disposed about the tubular body and engages the other ends of the knife members for biasing the other ends radially inwardly towards the tubular body. The handle end of the body is externally threaded and a collar nut, internally threaded, is adapted for threadably mating with the handle end. The nut has a shoulder angle selected for engaging a cam surface on the other ends of the knife members for applying an outward force thereto for camming the other ends of the knife members upwardly to pivot the knife edges downwardly through the registering slots into piercing contact with the limb.