Abstract: In an apparatus for separating particulate material of a selected size from particulate material of a smaller size, there is provided a screen assembly having a screen element for separating the particulate material. A tray assembly loosely supports impact elements in close relationship to the screen to dislodge particulate material from the apertures of the screen upon impact during operation of the apparatus which agitates the screen and tray assembly. The screen element and the tray assembly form an enclosure for the impact elements. The screen assembly and tray assembly are intermeshed and independently supported from one another and are adapted to separate upon removal from the apparatus.