This paper describes the first industrial application of the new DYNAFLEX oscillator developed by VAI on the two billet casting machines at Lech-Stahlwerke (Germany). Its main features are : no servohydraulic components, a system of leaf-springs arranged in cascade, simplicity of adjustment of stroke, frequency and wave form during casting. These factors suppress the need for maintenance of the oscillator, prevent mechanical backlash and result in a significant increase in machine availability and product quality, as well as in reduced maintenance costs.