A sleeved ultrasonic transducer (40) has a two-part head mass (42), including a threaded sleeve (44) and an outer housing (46) that are composed of different materials. The threaded sleeve (44) is preferably a metal such as titanium that provides superior thread strength for mating with a compression bolt (24), while the outer housing (46) is preferably aluminum or ceramic or other metal or non-metallic material that provides good thermal heat sink capacity and/or transmission of vibrational energy. The combination of the two components (44, 46) provides an improved ultrasonic transducer.