An impact pulverizer mounts a rotor concentrically within an octagonal shaped reduction chamber. The rotor has a substantially solid core and generally radially extending impact blades, each of which slopes in the axial direction of the rotor. Upon rotation of the rotor, the blades strike pulverizable material and propel the same radially of the chamber and against the interior walls thereof. The slope of the blades moves the pieces longitudinally of the chamber from the intake toward the egress end in a generally spiral rotational motion as the pieces ricochet off the interior walls and back against the rotor blades, striking each other as they so progress. The striking and ricocheting cause the pieces to break up and be reduced in size as they travel towards an outfeed opening.