A centrifugal blasting wheel is disclosed which includes a rotating plate carrying spaced radially extending blades for propelling particulate treating material. The inner ends of the blades terminate short of the axis of rotation of the wheel to form a central opening. Impelling means rotating with the wheel receives particulate material from a source and imparts radial and tangential velocity components to it so that it is picked up by the faces of the blades and travels along those faces to be thrown from their ends. The blades are of such a size that when the impelling means is removed from the central opening a new blade may be inserted therein and moved radially outwardly to be mounted on the plate while a reverse action along the same path of movement may be used to remove old blades.