This utility model provides a combined
tool holder using an NT50 to Capto C5 converter, comprising an NT50
tool holder, a connecting plate, and a Capto C5
tool holder. The connecting plate has a first inner hole and a second inner hole. One end of the NT50 tool holder is used to simultaneously engage with the inner
conical surface and end face of the spindle of a CNC turning and boring
machine. The other end of the NT50 tool holder is fixedly connected to the connecting plate by multiple first bolts. The Capto C5 tool holder is fixedly connected to the connecting plate by multiple screws. The Capto C5 tool holder includes a core sleeve, which is inserted into the second inner hole and interference-fitted with it. The inner wall of the core sleeve is triangularly conical, with the edges of the triangularly conical cone evenly distributed circumferentially and forming arcs. A second bolt for fixing the tool is threaded into the second inner hole. This utility model can achieve a tool change time of less than 2 minutes, a tool change
repeatability accuracy of less than 0.005 mm, excellent connection rigidity, and can achieve
cutting operations with a length-to-
diameter ratio of 5, meeting the requirements of
cutting operations.