An elongated assembly configured to releasably engage an ultrasonic transducer of an ultrasonic surgical instrument, the elongated assembly comprising: a waveguide defining a blade at a distal end, an engagement member at a proximal end, and including a torque adapter fixedly engaged thereabout towards the proximal end; a fixed sleeve and a movable sleeve each disposed about the waveguide and defining a proximal end and a distal end; a jaw member pivotably supported at the distal end of the fixed sleeve and operably coupled to the movable sleeve such that translation of the movable sleeve relative to the fixed sleeve pivots the jaw member relative to the blade between an open position and a clamping position; a drive assembly including a drive tube longitudinally fixed about the proximal end of the movable sleeve and slidably disposed about the fixed sleeve such that translation of the drive tube translates the movable sleeve relative to the fixed sleeve to pivot the jaw member between the open position and the clamping position, the drive tube slidably receiving the torque adapter therethrough; a torque housing slidably disposed about the drive tube, longitudinally fixed about the proximal end of the fixed sleeve, and fixedly engaged about the torque adapter; and a rotation knob 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 configured to impart rotation to the waveguide in response to rotation of the rotation knob to facilitate engagement of the engagement member of the waveguide with a complementary engagement member of an ultrasonic transducer up to a torque limit, and to decouple the rotation knob from the torque housing to inhibit application of additional torque to the waveguide above the torque limit. a waveguide defining a blade at a distal end, an engagement member at a proximal end, and including a torque adapter fixedly engaged thereabout towards the proximal end; a fixed sleeve and a movable sleeve each disposed about the waveguide and defining a proximal end and a distal end; a jaw member pivotably supported at the distal end of the fixed sleeve and operably coupled to the movable sleeve such that translation of the movable sleeve relative to the fixed sleeve pivots the jaw member relative to the blade between an open position and a clamping position; a drive assembly including a drive tube longitudinally fixed about the proximal end of the movable sleeve and slidably disposed about the fixed sleeve such that translation of the drive tube translates the movable sleeve relative to the fixed sleeve to pivot the jaw member between the open position and the clamping position, the drive tube slidably receiving the torque adapter therethrough; a torque housing slidably disposed about the drive tube, longitudinally fixed about the proximal end of the fixed sleeve, and fixedly engaged about the torque adapter; and a rotation knob 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 configured to impart rotation to the waveguide in response to rotation of the rotation knob to facilitate engagement of the engagement member of the waveguide with a complementary engagement member of an ultrasonic transducer up to a torque limit, and to decouple the rotation knob from the torque housing to inhibit application of additional torque to the waveguide above the torque limit.