RZ or ZZ Bearings Precision High Speed Bearings Deep Groove Ball Bearing, Sealed

RZ bearings use a rubber contact seal on one side. The seal lip touches the inner ring, which effectively blocks dust and retains grease — making RZ the better choice for moderately dusty or lightly contaminated environments. ZZ bearings use non-contact metal shields on both sides. Because the shield does not touch the inner ring, friction and heat generation are lower, making ZZ preferable for higher-speed, cleaner applications where minimising drag matters more than maximum sealing.

The easiest method is to read the model number stamped on your existing bearing — for example, "6205RZ" tells you the series (6200), the size code (05 = 25 mm ID), and the seal type (RZ). If the number is worn off, measure the inner diameter (ID), outer diameter (OD), and width with a calliper, then match those three dimensions to the variant options in this listing. All dimensions are listed in the format ID × OD × Width (mm).

Yes, every bearing in this listing arrives factory-greased and sealed. You do not need to add grease before fitting. Avoid washing the bearing with solvent before installation, as this removes the factory grease. If you are operating in an extreme-temperature or high-load environment, contact us to confirm the grease specification is appropriate for your application.

Yes. These bearings conform to ISO 15 dimensional standards, which means the envelope dimensions (ID, OD, and width) are identical to any other ISO-compliant bearing of the same model number, regardless of brand. As long as your OEM bearing carries the same model number — for example, 6304RZ — this bearing will fit the same housing and shaft without modification.

The 6000, 6200, and 6300 series are among the most widely used bearing families in general engineering. Typical applications include electric motor shaft support, power tool spindles, bicycle and skateboard wheel hubs, small pump impeller shafts, conveyor rollers, fans, and household appliance motors. The deep raceway geometry allows them to handle both radial loads and moderate axial (thrust) loads in either direction, making them versatile across a broad range of rotating machinery.

If you are doing a single repair and only need one bearing, the 1-piece option is the most straightforward. However, bearings in rotating assemblies often wear in pairs or sets — for example, a motor typically has one bearing at each end — so ordering 2–3 pieces covers both positions and gives you a spare. The 5- and 10-piece packs offer a lower per-unit cost and are practical if you maintain multiple machines, run a workshop, or want to keep common sizes in stock to avoid downtime on future repairs.

Common signs of a worn deep groove ball bearing include audible grinding, rumbling, or squealing during rotation; excessive heat at the bearing location; visible pitting, rust, or spalling on the raceways or balls; and increased radial or axial play when you rock the shaft by hand. If you detect any of these symptoms, replacing the bearing promptly prevents secondary damage to shafts, housings, and adjacent components.