An ultrasonic transducer for an ultrasonic flow measuring device, comprising a first housing part and a second housing part. The second housing part is axially guided in the first housing part and is so biased relative to the first housing part that, in a first state of the ultrasonic transducer, a first axial stop of the second housing part rests on a first axial stop of the first housing part, wherein, by applying, counter to the bias, a predetermined force on a second axial stop of the second housing part, the second housing part is axially shiftable, so that, in a second state of the ultrasonic transducer, the first axial stop of the second housing part is moved out of the first state.