Transducer and ultrasonic amplitude transformer with a cylindrical bore in the center are the key parts of ultrasonic vibration honing device. △ design is proposed to apply transducer and ultrasonic amplitude transformer with a cylindrical bore in the center to ultra- sonic vibration honing device on the basis of authors experiment. The design theory and a- coustic properties are investigated

which have been successfully applied to a vertical ultrason- ic vibration honing device

and make the abrasive stick expand under the rotating condition of machine tool spindle. Vertical ultrasonic vibration honing device developed by the authors has a practical significance.