Abstract: An assembly for a cylindrical cage which includes vanes made up of blades and end lugs. The end lugs and vanes are attached to a frame by a ring element with a fastener securing the ring element, end lug and blade to the frame. The end lugs are dimensioned and shaped so that when the end lugs of adjacent vanes are nested together, the vanes are spaced apart the desired amount and the angular relationship between vanes is maintained so that the gas flow path between adjacent vanes has the desired configuration. The blades can be made separate from or integral with the end lugs. The invention is particularly designed for use in mounting guide vanes in a cage type air classifier for classifying particulate materials.