1. Product Overview B40-18 non-standard single-row open deep groove ball bearing, overall dimension 40mm inner bore × 68mm outer diameter × 18mm width, fully interchangeable with original NSK B40-18, widely matched to mainstream Japanese CVT small auxiliary control shafts and mini differential assemblies. Open design without rubber seals, equipped with stamped low-carbon steel cage and factory standard C0 internal clearance, C3 clearance customizable on demand. It bears