FRM / FRB locating rings are used to axially position bearings within a housing bore, preventing movement and ensuring correct alignment during operation. They are typically fitted into the housing groove alongside self-aligning ball bearings or spherical roller bearings, allowing the bearing to be positively located on one or both sides.

By controlling axial displacement, locating rings help maintain consistent load distribution across the rolling elements, reducing wear and improving overall bearing life. They are especially useful in applications where thermal expansion, vibration, or varying loads could otherwise cause the bearing to shift within the housing.