The characteristics of inner hole turning are: in a semi closed state, it is difficult to observe the chip removal situation, which affects the processing quality.Based on its characteristics. We have two types of inner hole turning tools available for selection One is made of hard alloy materia and another type is Material 42CrMo .The hard alloy tool holder has excellent vibration resistance and damping performance, suitable for small and deep hole machining and 42CrMo material holder whole forging processing make the turning tool with long service life, better wear-resistantce,strength and rigidity,high working efficiency.