1. Product Overview The 6306‑2RS1/C3 single row deep groove ball bearing adopts double-sided 2RS1 contact NBR rubber seals and C3 enlarged radial clearance. The expanded internal clearance compensates thermal expansion under long-term high-speed and high-temperature running to prevent bearing locking. Double contact rubber seals effectively isolate dust, water mist and impurities and retain internal grease. Widely used in high-speed medium-large motors, water pumps, blowers