Bearing Seal Types
Pick an open, shielded or rubber-sealed bearing by answering four questions on dust, moisture, washdown and speed. Shows the suffix to order.
The seal type is the suffix on the model number — 6205, 6205 ZZ and 6205 2RS are the same bearing with a different seal arrangement. Answer the questions below to decide which one fits the application.
Seal type selector
- Is the bearing inside a sealed housing or gearbox that already keeps out dust and water? If yes, open is usually enough and keeps regreasing simple.
- Is there washdown, dust or fine debris in the environment (food processing, agriculture, outdoor equipment)? If yes, 2RS seals against contamination more completely than ZZ.
- Does the application need low running friction at higher speed? If yes, ZZ adds less drag than a rubbing seal.
- Is occasional light spray or dust the main concern, with no washdown? ZZ is normally sufficient and keeps the lower friction of an unsealed contact.
Seal types compared
| Suffix | Structure | Keeps out | Friction | Lubricant |
|---|---|---|---|---|
| (none, open) | No shield or seal | Nothing — relies on the housing | Lowest | Added through the housing |
| Z or RS | One shield or one seal; the other side is open | Only on the closed side | Low (Z) / slightly higher (RS) | Grease, not oil |
| ZZ | Two metal shields, non-contact | Larger dust and debris | Low | Greased at the factory |
| 2RS | Two rubber seals, light contact | Dust, moisture, washdown spray | Slightly higher | Greased at the factory |
Conclusion
Once you have picked a seal type, add the suffix to the model number when you send your inquiry — for example 6205-2RS rather than 6205. FULI supplies deep groove ball bearings in open, ZZ and 2RS as standard, and in single-sided Z and RS as well; see deep groove ball bearing for the full size range, or send the model and seal type to sales@fuli-bearings.com for a quotation.
For how ZZ and 2RS compare on dust, water and speed, and what else to write on the order line, read ZZ vs 2RS bearings.
FAQ
What is the difference between ZZ and 2RS?
ZZ is two thin metal shields pressed into the outer ring, close to the inner ring but not touching it; it keeps out larger debris and adds little friction. 2RS is two rubber seals that lightly contact the inner ring, sealing against dust and moisture more completely but adding a small amount of friction and lowering the speed limit. Both are greased at the factory.
Can an open bearing be regreased more easily than a sealed one?
Yes. An open bearing has no shield or seal, so grease can be applied directly and old grease flushed out; it is the usual choice where the bearing sits inside a sealed housing or gearbox that already keeps out contamination.
Which suffix do I add to the model number?
ZZ for two metal shields, 2RS for two rubber seals, nothing for open. For example 6205 open, 6205 ZZ, 6205 2RS. For a shield or seal on one side only, write Z or RS, for example 6205-Z; the other side is open. FULI supplies these single-sided bearings as well.