Abstract: An agitator device for use in a reactor tank having a longitudinal shaft that is journaled in the tank and oscillated by an external power source. A hub assembly composed of an upper and lower cylindrical portion support a blade holder which is adjustable about an axis that is normal to the axis of the shaft. The upper and lower cylindrical portions of the hub assembly are clamped together to secure the blade holder in its adjusted position. The blade is pivotally adjustable on the blade holder about an axis that is normal to the axis of rotation or adjustment of the blade holder.