Various ultrasonic surgical instruments are disclosed. At least one disclosed surgical instrument includes a waveguide including a blade and a transducer base plate. The transducer base plate coupled to the waveguide to define a joint at an interface between the waveguide and the transducer base plate. The transducer base plate including first and second sides defining corresponding first and second flat faces configured to receive first and second piezoelectric elements. The first and second piezoelectric elements are configured to operate in a D31 mode.
