A throwing wheel assembly including a wheel and a series of throwing blades mounted in radial channels in the wheel formed with mating dovetail wing portions on the slot sides and a projecting at the base of the blade. A sloping grove in the bottom of each channel engages a projecting ramp feature on the base of the mating blade received therein to cam the blade outwardly and thereby create a tight fit of the dovetail portions and to lock the blades in position.