An ultrasonic tool is disclosed with a handpiece (300, 500, 806) containing coils (304A-304D; 504A-504D; 804A-804B) that produce an electromagnetic field that vibrates a magnetic rod (102, 702A, 702B, 820) of a moveable pin transducer (MPT) 100 disposed within the handpiece. Ultrasonic vibrations are produced when the coils are selectively powered by an ultrasonic signal generator, which can include a stepper motor control apparatus (1300, 1400). A tip 106 can be removably attached to an MPT 100. A channel (708A, 708B) in the magnetic rod (700A, 700B) can allow fluidic communication with a handpiece fluid supply channel (310, 510). A method of vibrating a tool can include controllably energizing at least one electromagnetic coil contained within a handpiece to vibrate a magnetic rod and an attached tip. The method can include varying the energy to at least one of the electromagnetic coils with a stepper motor control apparatus.