Abstract: A preferred embodiment of a workpiece finishing system impinges a grit and fluid slurry onto a workpiece and then recycles the slurry for subsequent reuse. In another aspect of the present invention, a recovery tank is used for generally settling and concentrating the grit in the slurry, and for separating out a portion of the fluid from the grit. A further aspect of the present invention provides a venturi-type nozzle for expelling the grit and fluid onto a workpiece, wherein the nozzle has a selectively movable inlet thereby varying the slurry concentration properties of the nozzle.

Abstract: A punch is disclosed having a hollow removable blade for punching an opening in a sheet of cardboard or other similar material. The blade has a beveled cutting edge about an inlet end. The diameter of the blade increases from the inlet end to the outlet end to prevent the slugs from becoming compacted in the blade.

Abstract: A punch for cutting an elongated slug from material has a removable hollow blade having first and second sides, one side shorter than the other. The blade is received in a body having upper and lower seats for receiving the first and second sides of the blade. An opening in the body allows for passage of the severed slug.