A system for assembling an ultrasonic transducer to an ultrasonic instrument comprising a housing having a distal and proximal end and a waveguide extending distally from the housing and the waveguide defining a longitudinal axis, the system comprising: a torque receiving element aligned with the longitudinal axis for receiving a torque delivery element, the torque receiving element comprising two or more spline gears, each gear comprising a cam ramp and a flat portion; a body having an axis comprising cantilever arms aligned in an annular fashion about the axis and the gears, the cantilever arms adapted to engage the ramp portions of the gears when the body is rotated in a first direction about the longitudinal axis, thereby imparting to the torque receiving element a limited torque sufficient to operatively couple an ultrasonic surgical instrument to an ultrasonic transducer, and the cantilever arms engaging the flat portions of the gears when the body is rotated in a second, opposite direction about the longitudinal axis, thereby imparting to the torque receiving element a torque in proportion to the force applied to the torque delivery element facilitating removal of the ultrasonic surgical instrument from the ultrasonic transducer; and characterised in that: an inner curved surface of each cantilever arm forms part of the inner surface of the body and an outer curved surface of each cantilever arm forms part of the outer surface of the body, and in that rotation of the body in a first direction, causes the cantilever arms to flex away from the longitudinal axis. a torque receiving element aligned with the longitudinal axis for receiving a torque delivery element, the torque receiving element comprising two or more spline gears, each gear comprising a cam ramp and a flat portion; a body having an axis comprising cantilever arms aligned in an annular fashion about the axis and the gears, the cantilever arms adapted to engage the ramp portions of the gears when the body is rotated in a first direction about the longitudinal axis, thereby imparting to the torque receiving element a limited torque sufficient to operatively couple an ultrasonic surgical instrument to an ultrasonic transducer, and the cantilever arms engaging the flat portions of the gears when the body is rotated in a second, opposite direction about the longitudinal axis, thereby imparting to the torque receiving element a torque in proportion to the force applied to the torque delivery element facilitating removal of the ultrasonic surgical instrument from the ultrasonic transducer; and characterised in that: an inner curved surface of each cantilever arm forms part of the inner surface of the body and an outer curved surface of each cantilever arm forms part of the outer surface of the body, and in that rotation of the body in a first direction, causes the cantilever arms to flex away from the longitudinal axis. an inner curved surface of each cantilever arm forms part of the inner surface of the body and an outer curved surface of each cantilever arm forms part of the outer surface of the body, and in that rotation of the body in a first direction, causes the cantilever arms to flex away from the longitudinal axis.