Abstract: A shear ring screw adopted for use with polymer extrusion or injection molding machinery including a first stage feeding portion (26), a second stage ring section (28) and a third stage tip section (44B). It would be generally aimed at improving the melting, dispersing and spatial distributive mixing action of such machinery. This would be generally achieved through the use of shear rings with a series of angled ports or holes. The ring section disperses fillers or additives by powerful shearing and stretching force created by relative ring to ring and ring to screw movements. The molten mixture could be further mixed and homogenized by the tube tip section which have plural of port members on radial directions and a conical shaped flow channel in axial direction.