An ultrasonic surgical instrument includes an elongated assembly releasably engagable with an ultrasonic transducer and including a waveguide having a blade at a distal end and a torque adapter towards a proximal end. Fixed and movable sleeves are disposed about the waveguide and support and operably couple to a jaw member at the respective distal ends thereof. A drive tube is fixed to the movable sleeve such that translation of the drive tube pivots the jaw member relative to the blade. A torque housing is slidably disposed about the drive tube, longitudinally fixed about the fixed sleeve, and fixedly about the torque adapter. A rotation knob is longitudinally fixed about the torque housing and operably coupled to the torque housing such that the torque housing and the rotation knob cooperate to define a torque wrench inhibit application of additional torque to the waveguide above a torque limit.