This report is applicable to magnetostrictive transducers, of both laminated metal and ferrite types, designed for producing sonic or ultrasonic acoustic power in liquid or solid media, and for different kinds of ultrasonic processing such as cutting, welding, chemical processing, etc. Transducers for information carrying signals are excluded. The transducers, which may be sonic or ultrasonic, operate at the resonance frequency and are supplied from electric power generators. It also applies with some modifications to special transducers, for example those designed for application to molten metals, etc. In this report only transducers with a single working frequency of resonance are considered.