Relieving Lathe

a metal-cutting machine tool of the lathe group for machining the back surfaces of the teeth of multiblade cutting tools (for example, form cutters and tap borers) to impart to them a curved (“relieved”) shape. The tool is a form tool whose shape is a mirror image of the shape of the piece to be worked; it is mounted on a slide rest, and the workpiece is mounted on pointed journals (directly or on a mandrel). The workpiece is rotated by the lathe spindle. The slide rest and form tool are moved transversely by a rotating cam, which also returns the slide rest to its initial position when the form tool reaches the tooth space of the tool being machined.