32018 X bearing
90 × 140 mm · dynamic rating 208 kN · static rating 270 kN. Dimensions, load ratings, designation meaning, life estimates and equivalent parts.
32018 X specification
| Designation | 32018 X |
| Type | Tapered roller bearing |
| Series | 320 steep-angle |
| Bore diameter d | 90 mm |
| Outside diameter D | 140 mm |
| Basic dynamic load rating C | 208 kN (208,000 N) |
| Basic static load rating C0 | 270 kN (270,000 N) |
| Ratio C0/C | 1.30 |
| Speed guide, grease lubrication | 4,300 rpm |
| Life exponent p | 10/3 (roller bearing) |
Values come from the Rotec AI bearing catalogue and are indicative. Confirm against the manufacturer's current catalogue before ordering. Not every dimension (such as width) is listed here.
What the designation 32018 X means
| Code | Meaning |
|---|---|
| 320 | Tapered roller bearing, steep contact angle series (higher axial capacity) |
| 18 | bore code "18" = 18 × 5 = 90 mm |
| X | Boundary dimensions changed to conform to ISO |
Basic rating life of the 32018 X
Basic rating life is L10 = (C / P)p million revolutions, where P is the equivalent dynamic load and p = 10/3 (roller bearing). For a 32018 X with C = 208 kN, the table shows what that gives at different load levels. It is the ISO 281 basic life only: it does not include lubrication, contamination, misalignment or reliability modifiers.
| C / P | P as share of C | L10 (million rev) | L10 at 1,500 rpm | L10 at 3,000 rpm |
|---|---|---|---|---|
| 3 | 33.3% | 39 | 430 | 220 |
| 5 | 20.0% | 214 | 2,400 | 1,200 |
| 8 | 12.5% | 1,024 | 11,400 | 5,700 |
| 12 | 8.3% | 3,956 | 44,000 | 22,000 |
For example, a C / P of 5 means the equivalent load is 41.6 kN on this bearing. Use the Load Calculator to work out P for your actual radial and axial loads.
Equivalents of the 32018 X
Brand-by-brand equivalents for this exact designation are not yet in the Rotec AI cross-reference tables. The Cross-Reference tool accepts SKF, FAG, NSK, NTN, Timken, Koyo and NRB designations, and shows what is catalogued.
Where the 32018 X is used
Tapered roller bearings are chosen for: Combined radial and axial load; stiffness. Typical equipment: Wheel hubs, gearboxes, rail wheelsets, construction/agri equipment. Usually adjusted/preloaded; paired arrangements common.
Other sizes in the same series
The 32018 X is size 15 of 17 in the Rotec AI catalogue for the “320 steep-angle” series. The next size down, the 32017 X, has a bore of 85 mm and a dynamic rating of 171 kN. The next size up, the 32019 X, has a bore of 95 mm and a rating of 206 kN (-1%).
Common problems on bearings like the 32018 X
Most field failures trace back to lubrication, contamination, fits and alignment rather than the bearing itself. These guides explain how to recognise and prevent them:
Questions about the 32018 X
What are the dimensions of a 32018 X bearing?
The 32018 X has a bore of 90 mm and an outside diameter of 140 mm. It is a tapered roller bearing. Series: 320 steep-angle.
What is the load rating of a 32018 X bearing?
In the Rotec AI catalogue the 32018 X has a basic dynamic load rating C of 208 kN and a basic static load rating C0 of 270 kN. Always confirm against the manufacturer's current catalogue.
What is the equivalent of a 32018 X bearing?
Brand equivalents for the 32018 X are not yet in the Rotec AI tables. Use the Cross-Reference tool to check other designations.