摘要 |
A method and a tool for expanding the outside diameter and forming grooves on the inside surface of a tube. The tool comprises an axially extending mandrel, a centering portion, and a grooving portion. The centering and grooving portions of the tool are both secured to the mandrel, with the grooving portion located axially rearward of the centering portion. The centering portion radially projects outward of the mandrel, and the grooving portion is coaxial with and radially projects outward of the central portion of the tool. The central portion defines a smooth annular surface to engage and partially expand the tubes, inside and outside diameters, to guide the tube onto the grooving portion, and to maintain the grooving portion centered within the tube. The grooving portion defines an outside surface to expand the tube further, and preferably includes a plurality of external fins to form grooves on the inside surface of the tube. |