A locking device employing a break away interface member rigidly coupled to a seating member for use in securing a stabilization member within a bone stabilization system. The bone stabilization system includes a bone anchor, a stabilization member, a coupling mechanism and a locking device. The locking device is structured to engage the coupling mechanism and the coupling mechanism is configured to couple the stabilization member to the bone anchor. The locking device, which is configured to thread into the coupling mechanism, includes an interface member rigidly connected to the seating member. The interface member breaks away from the seating member at a break-off junction to drop into contact with the stabilization member and to secure the stabilization member in the coupling mechanism following continued engagement of the seating member into the coupling mechanism.