Abstract: A machining method, for a CNC-lathe for forming a predefined thread in a work piece, includes the steps of: rotating the metal work piece around a rotational axis thereof; moving a threading tool along a longitudinal direction through a set of passes, wherein the longitudinal direction is parallel/coinciding to the rotational axis; oscillating the threading tool in a radial direction during a first pass and first frequency, the threading tool moving between a first radial distance (D1) and a second radial distance (D2), (D1) being greater than (D2); oscillating the threading tool in a radial direction during a second pass and second frequency, the threading tool moving between a third radial distance (D3) and a fourth radial distance (D4), (D3) being greater than (D4) and smaller (D1), and (D4) being smaller than (D2); and during a last pass moving the tool without oscillation in the radial direction.

Abstract: A turning method for a computerized numerical control lathe includes providing a turning tool having a cutting portion, the cutting portion including a first nose portion, the first nose portion including a first cutting edge, a second cutting edge, and a convex nose cutting edge connecting the first and second cutting edges, wherein the first and second cutting edges are straight or substantially straight in a top view. The method further includes providing a metal work piece, rotating the metal work piece around a work piece rotational axis, and making a first pass where the first cutting edge is active and the second cutting edge is inactive. A first machined surface is generated by the convex nose cutting edge, and during at least a portion of the first pass, an entering angle and an angle, which the first cutting edge forms with the work piece rotational axis, simultaneously varies.