Abstract: An ultrasonic handpiece wherein the entire assembled handpiece may be sterilized with an ingress of the sterilizing fluid into the interior of the handpiece. The handpiece is formed with an elongated housing sleeve and a coil unit for establishing an alternating magnetic field located therein. The housing sleeve and coil unit is assembled such that crevices are formed between the ends of the housing sleeve and coil unit, thus allowing steam, chemicals and heat to pass in and out of the interior of the handpiece for more rapid and thorough sterilizing of the handpiece. Further, the coil unit is not potted to the housing sleeve in order to allow for different thermal coefficients of expansion between materials without the buildup of undue stress.