An ultrasonic surgical instrument includes a body, an ultrasonic supported by the body, a shaft extending distally from the body and defining a shaft axis, a waveguide extending distally through the shaft, and an end effector arranged at a distal end of the shaft. The end effector includes an ultrasonic blade coupled to a distal end of the waveguide and having a primary blade treatment surface configured to treat tissue, and a clamp arm coupled to the distal end of the shaft. The shaft and the waveguide are selectively rotatable relative to one another about the shaft axis through a predefined range of angular motion between an assembly state and an operational state. In the assembly state, the clamp arm and the primary blade treatment surface are rotationally offset from one another. In the operational state, the clamp arm and the primary blade treatment surface are rotationally aligned.