Official Answer
Answer
Self-locking spiral rings feature a small tab on an inner turn that 'locks' into a slot on an outer turn. This prevents the ring from expanding at high RPM or under heavy vibration. The challenge during installation is ensuring the tab correctly clicks into the slot. If the ring is improperly seated, the locking feature will not engage, and the ring may fail at speeds lower than intended. Technicians often use a 'click' test or visual inspection with a borescope to confirm engagement. In aerospace turbine assemblies, this self-locking feature is critical because a standard ring would eventually 'vibrate out' of the groove even if the axial thrust load is low.
