Abstract: Apparatus for deforming the surface of a cylindrical metal portion of a workpiece at and adjacent its end includes a rotating disk having radially extending slots. Slide members having roller deforming tools rotatably journalled at one end are positioned in a respective slot with the tool disposed radially inwardly, the tools having axes of rotation parallel to the axis of rotation of the disk. A follower member is fastened to the other end of the slide member and extends outwardly from the slot beyond the circumference of the disk. The disk is mounted within an annular shell having a tapered internal cam surface varying in diameter in the axial direction. The shell is mounted for rotation with the disk but axially moveable relative to the disk.