Bearing load ratings — how to read Cr and Cor
2026-10-29
The actual Cr / Cor range across our 100 base models, the ratio pattern, why seal variants do not change them, and what these two numbers cannot tell you.
All 100 of our base models record a basic dynamic load rating Cr and a basic static load rating Cor. This page covers only those two columns: what they mean, where they fall in our catalogue, when they do not change, and what they cannot answer.
What the two numbers mean
What Cr is
Cr is the basic dynamic load rating: the constant radial load, in magnitude and direction, that the bearing can carry for its rated life. It is the first reference point for "how much can this bearing carry" — a reference, not a permitted working load.
What Cor is
Cor is the basic static load rating: the maximum load the bearing can take at rest or at very low speed without permanent deformation at the rolling contact exceeding the specified limit. It answers "will it be dented while standing still".
In one line: read Cr when it turns, read Cor when it stands.
What the table actually records
Range across the 100 base models
Measured on the open-type rows (100 rows, every one has both values):
| Item | Minimum | Maximum |
|---|---|---|
| Cr | 775 N (685) | 81,900 N (6312) |
| Cor | 320 N (685) | 52,150 N (6312) |
A few common sizes sit in the middle:
| Model | Cr | Cor |
|---|---|---|
| 605 | 1,440 N | 550 N |
| 608 | 3,310 N | 1,370 N |
| 6000 | 4,550 N | 1,950 N |
| 6205 | 14,000 N | 7,900 N |
| 6305 | 22,450 N | 11,550 N |
| 6312 | 81,900 N | 52,150 N |
Is there a pattern in the Cr / Cor ratio
Yes, and the spread is narrow: minimum 1.09 (6810), median 1.83, maximum 2.67 (635).
- A low ratio (≈1.1) belongs to thin-section, large-bore models such as 6810, 6809 and 16010 — they are relatively stronger in static capacity.
- A high ratio (≈2.6) belongs to miniature models such as 605, 625 and 635 — relatively stronger in dynamic capacity.
So comparing Cr alone loses information: two models with the same Cr can differ twofold in Cor.
When these numbers do not change
Do seal variants change the load rating
No. Across 100 base models × 7 seal forms, Cr and Cor are identical in every case — zero exceptions.
A 6205 is Cr 14,000 N / Cor 7,900 N whether it is Open, ZZ or 2RS. The seal changes the speed limit (see speed and lubrication), not the load capacity.
Why the N and kN columns agree
The source table carries both N and kN column pairs. We cross-checked every row — 700 rows, zero mismatches (1,440 N corresponds to 1.44 kN, for example).
If you work in kN, multiply by 1000 to get N. There is no need to round to a precision the table does not contain.
How to use them, and how not to
Comparing two models
- Compare
Crfirst: at the same bore, a higherCrcarries more dynamic load. - Then check
Cor: with shock loads or long idle standing loads,Coris the limiting figure. - Then look at the ratio: high means dynamic-oriented, low means static-oriented.
What they cannot tell you
- No life calculation: L10 rating life needs equivalent dynamic load and speed. The parameter table contains neither input, so this site publishes no life figures.
- No equivalent load: how radial and axial loads combine depends on your application, not on the table.
- Not a permitted working load:
Cris a rating; engineering practice applies application factors, and those factors are not in the table. - No noise, torque or starting friction: those fields do not exist in the source table.
For how to narrow down across load, speed, size and seal in four steps, see how to choose a model. If you need a calculation against your duty cycle, send us the conditions and we will look at them together (contact us). This site stands behind the fields the table records — numbers that are not in the table are not invented here.
The two extremes quoted above can be checked directly: 6312 (highest Cr, 81,900 N) and 685 (lowest Cr, 775 N).