Abstract:From reducing cutting force and cutting heat, slender shaft machining was explored. An activity top was designed, to meet the need of heated elongation of slender shaft and to avoid thermal deformation. A set of simple thread die tooling was designed, to improve the quality of screw thread processing. Three jaw ball was contacted with the rest,then parts move was restricted, it only could rotate around the axis, reducing the cutting vibration and deformation. Rational cutting parameters were chosen, reasonable cutting tool parameters were designed, the precision of lathe was adjusted.