Do Sealed Bearings Need to Be Refueled?

No, you don't need to Bearings with sealed covers on both sides (whether rubber or steel stamped seals) do not require refueling.

Bearing designers, in order to achieve the most ideal life value of bearings, fill what label of grease, grease filling, is the best and most scientific solution after countless actual experiments. It is generally believed that the life of grease consumption is equivalent to the life of bearings. In addition, the design of the seal cover, the distance from the inner ring, or contact, or non-contact, or maze are designed. The disassembly of the seal cover when refueling will inevitably affect its effect, which in turn will affect the service life of the bearing.

Take NSK as an example: 6305DDUCM NS7S, NS7 is the oil label, its chemical composition is strictly confidential. S is the mark of the amount of grease filling, but also strictly confidential!