The STO/NAST series refers to a type of needle roller bearing with a locating snap ring, designed for applications requiring secure axial positioning in a compact space. The "STO" and "NAST" designations typically indicate variations in the snap ring configuration or internal design (e.g., with or without an inner ring). These bearings integrate a needle roller assembly (with or without a cage) and a hardened outer ring, complemented by a snap ring groove and a removable snap ring on the outer ring. This snap ring locks the bearing axially when installed into a housing, preventing movement and simplifying assembly without additional components. They are ideal for high-radial-load applications where axial space is limited and precise bearing positioning is critical.
