PURPOSE: To maintain high performance by using an extremely simple constitution by a method wherein a pin for transmitting friction torque, composed of stainless, etc., on an ultrasonic elliptical vibration generating surface in a connector, is projected from the ultrasonic elliptical vibration generating surface.

CONSTITUTION: Pins 10 for transmitting friction are fixed to ultrasonic elliptical vibration generating surfaces (the nose surfaces of beams 4) 9 in a connector 5 having a resonator 4 and the beams 4 respectively, and the pins 10 consist of steel, stainless or ceramics having HRC 40 or above. The pins 10 are made up of pin head sections 21 and press-fitting shaft sections 22 having a diameter smaller than the pin head sections 21, and the press-fitting shaft sections 22 are press-fitted into holes 23 in the axial core direction shapedly provided to the nose surfaces 9 of each beam section, thus press-fitting and fastening the pins 10 to separate nose surface 9. The height of projection from each nose surface 9 is kept constant. Accordingly, the pins 10 have high hardness and abrasion resistance, thus stabilizing the conditions of revolution on a torque transmission surface.