At a glance
G10 balls
The lower numerical grade generally specifies tighter geometry tolerances within the same grading standard.
Specify when the ball supplier's tolerances are required by the bearing or precision mechanism drawing.
G25 balls
A less restrictive grade than G10 within a compatible grading system; request the actual tolerance table.
Specify when those tolerances meet the designed mechanism and the procurement standard.
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 | G10 balls | G25 balls |
|---|---|---|
| Compared object | Individual balls and lots | Individual balls and lots |
| Geometry requirement | Generally tighter within the same standard | Generally looser within the same standard |
| Dimensions to check | Diameter variation, spherical form and lot variation | The same measures |
| Surface finish | Read the standard's roughness requirement | Read the standard's roughness requirement |
| ABEC relationship | No direct one-to-one conversion | No direct one-to-one conversion |
| Complete bearing | Raceways, assembly and preload still matter | Raceways, assembly and preload still matter |
Before you choose
- ISO and ABMA grade labels and suffixes must be compared under their own standards.
- Do not interpret the number as a universal micrometre tolerance; units and measured property matter.
- The catalogue's bearing precision field does not establish the ball grade used inside it.
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
Does G10 mean ABEC 10?
No. Ball grades and assembled-bearing tolerance classes are different systems.
Can I replace bearing balls with a tighter grade?
Not as an automatic repair. Diameter group, raceway condition, internal geometry and assembly requirements must also match.
Reference basis & limits
- NHBB — Engineering reference: ball grades
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.