Patent ID: 8070401

Claim:
An apparatus for improving a centrifugally-cast tube comprising: a first and second guide adapted to hold the tube; a shaft adapted to pass longitudinally through a bore of the tube; one or more convex assemblies of cutting tools mountable on the shaft and including only a plurality of cutting inserts with a convex profile for forming grooves, the one or more convex assemblies comprising successive convex cutting tools, successive in the longitudinal direction of the shaft, of increasing dimensions that are adapted to mechanically form a profile of grooves within the bore of the tube; and one or more concave assemblies of cutting tools mountable on the shaft as an alternative to the one or more convex assemblies of cutting tools and including only a plurality of cutting inserts with a concave profile for forming bosses, the one or more concave assemblies comprising successive concave cutting tools, successive in the longitudinal direction of the shaft, of increasing dimensions that are adapted to mechanically form a profile of bosses within the bore of the tube.