At a glance
Sealed
Integral closures help retain grease and protect the rolling contact.
Choose for a contained grease charge and a maintenance plan that does not require direct access to the rolling elements.
Open
No integral seal or shield separates the rolling elements from the housing interior.
Choose for oil lubrication, planned relubrication or a machine with suitable external seals.
Key differences
Typical design distinctions. The complete designation and current product specification take precedence.
Swipe the table horizontally to see both options →
| What to compare | Sealed | Open |
|---|---|---|
| Protection | Provided partly by integral seals | Provided by the housing and shaft seals |
| Lubricant supply | Often pregreased | Oil or grease supplied by the arrangement |
| Access | Closures restrict access | Rolling contact is accessible |
| Drag | Contacting closures add torque | No integral closure torque |
| Speed decision | Use the sealed variant's rating | Check lubrication and heat balance |
| Maintenance | Grease life may determine replacement | Lubricant condition and replenishment govern service |
Before you choose
- Open does not mean dry-running.
- A sealed bearing inside an oil system needs a lubrication-path check.
- Do not infer longer life solely from closure type; contamination, load and temperature remain decisive.
Check the actual model
Search a full designation, inspect its technical data, then compare candidate records. Similar names or dimensions do not guarantee interchangeability.
Filters show recorded catalogue attributes. Open each candidate to confirm its exact specification.
A few things worth clarifying
Can an open bearing replace a sealed one?
Only if the surrounding assembly supplies equivalent lubricant retention and contamination control.
Is open always faster?
It removes closure drag, but cage, lubricant, load and heat dissipation still determine the allowable speed.
Reference basis & limits
- SKF — Rolling bearings catalogue, publication 17000
- NSK — Single-row deep groove ball bearings: features and closure designations
Independent explanatory content; not a manufacturer endorsement or approval of a replacement. Verify current product data, fits, lubrication and operating conditions before applying a comparison.