Cold Punching of Bakelite by Using the Ultrasonically Vibrated Punch

In this paper, the opportunity of ths study is described and the punching mechanism is considered and the outline of this effective ultrasonic punching is investigated. By using the conventional press, the crack is occurred in cold punching and so is generally heated, but in this ultrasonic cold punching, the crack is never observed and moreover, the punching resistance is decreased to 1/2∼1/8 that of conventional punching.