The ultrasonic oscillator is a kind of ultrasonic oscillator used to generate turbulence in the neighborhood of calendered metal workpieces such as newly formed wire strands. An ultrasonic oscillator for subjecting a workpiece to a turbulent liquid flow comprises a first groove; A liquid disposed in the first tank, wherein a workpiece is immersed in the liquid during operation of the oscillator; A transducer connected to the first tank so as to be in mechanical contact with the liquid, the transducer being structured to generate ultrasonic waves in the liquid, thereby generating turbulence in the liquid adjacent to the workpiece; And a transducer driving system connected to the transducer for causing the transducer to oscillate at a frequency of at least 1KHZ.