1. Product Overview B31-10 non-standard single-row narrow open deep groove ball bearing, overall dimension 31mm inner bore × 50mm outer diameter × 10mm narrow width, interchangeable with original NSK B31-10 and HTFB31-10 equivalent model, widely matched for Japanese CVT tiny control valve shafts and small differential auxiliary assemblies. Open design without rubber seals, equipped with stamped low-carbon steel cage and factory standard C0 internal clearance, C3 clearance