A surgical instrument, comprising: (a) an instrument body; (b) an ultrasonic transducer assembly rotatably mounted along a longitudinal axis within the instrument body; and (c) a slip lock operatively connected to the instrument body and including: (i) a lock member configured to be selectively moved between an unlocked position and a locked position, and (ii) an arrester having a catch portion and a deflectable portion, wherein the deflectable portion is configured to deflect relative to the ultrasonic transducer assembly, wherein the ultrasonic transducer assembly is configured to be selectively rotated about the longitudinal axis relative to the instrument body with the lock member in the unlocked position, wherein the catch portion is configured to seize the ultrasonic transducer assembly with the lock member in the locked position to thereby selectively inhibit rotation about the longitudinal axis relative to the instrument body for rotatably coupling with the acoustic waveguide up to a predetermined torque, and wherein the deflectable portion is configured to deflect relative to the ultrasonic transducer assembly upon receiving a torque greater than the predetermined torque such that the catch portion releases the ultrasonic transducer assembly to slip relative to the catch portion for limiting coupling of the ultrasonic transducer assembly with the acoustic waveguide to the predetermined torque wherein the instrument body includes a switch channel, wherein the lock member includes a lock switch movably mounted in the switch channel, and wherein the lock switch is configured to be manipulated by a user between the locked and unlocked positions, wherein the slip lock further includes an engagement feature connected to the ultrasonic transducer assembly, wherein the arrester is operatively connected to the lock switch and is configured to selectively move between a disengaged position and an engaged position as the lock switch is respectively moved between the unlocked position and the locked position, and wherein the catch portion of the arrester is configured to engage the engagement feature in the engaged position to inhibit rotation of the ultrasonic transducer assembly, and characterised in that the lock switch is configured to selectively translate along a transverse direction between the unlocked and the locked position to selectively translate the arrester transversely between the disengaged position and the engaged position. (a) an instrument body; (b) an ultrasonic transducer assembly rotatably mounted along a longitudinal axis within the instrument body; and (c) a slip lock operatively connected to the instrument body and including: (i) a lock member configured to be selectively moved between an unlocked position and a locked position, and (ii) an arrester having a catch portion and a deflectable portion, wherein the deflectable portion is configured to deflect relative to the ultrasonic transducer assembly, wherein the ultrasonic transducer assembly is configured to be selectively rotated about the longitudinal axis relative to the instrument body with the lock member in the unlocked position, wherein the catch portion is configured to seize the ultrasonic transducer assembly with the lock member in the locked position to thereby selectively inhibit rotation about the longitudinal axis relative to the instrument body for rotatably coupling with the acoustic waveguide up to a predetermined torque, and wherein the deflectable portion is configured to deflect relative to the ultrasonic transducer assembly upon receiving a torque greater than the predetermined torque such that the catch portion releases the ultrasonic transducer assembly to slip relative to the catch portion for limiting coupling of the ultrasonic transducer assembly with the acoustic waveguide to the predetermined torque wherein the instrument body includes a switch channel, wherein the lock member includes a lock switch movably mounted in the switch channel, and wherein the lock switch is configured to be manipulated by a user between the locked and unlocked positions, wherein the slip lock further includes an engagement feature connected to the ultrasonic transducer assembly, wherein the arrester is operatively connected to the lock switch and is configured to selectively move between a disengaged position and an engaged position as the lock switch is respectively moved between the unlocked position and the locked position, and wherein the catch portion of the arrester is configured to engage the engagement feature in the engaged position to inhibit rotation of the ultrasonic transducer assembly, and characterised in that the lock switch is configured to selectively translate along a transverse direction between the unlocked and the locked position to selectively translate the arrester transversely between the disengaged position and the engaged position. (i) a lock member configured to be selectively moved between an unlocked position and a locked position, and (ii) an arrester having a catch portion and a deflectable portion, wherein the deflectable portion is configured to deflect relative to the ultrasonic transducer assembly,