NU210 bearing: complete specifications & equivalents
The NU210 is a ISO 15 radial bearing sized 50 x 90 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 50 mm |
| Outer diameter D | 90 mm |
| Width B | 20 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 73.5 kN |
| Basic static load rating C0 | 69.5 kN |
| Fatigue load limit Pu | 8.8 kN |
| Reference speed (thermal) | 8500 rpm |
| Limiting speed (mechanical) | 9000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 470 g |
| Manufacturer designation | NU 210 ECP |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & NU200-series range
| Bore d | 1.969 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.787 in |
| ISO bore code | 10 |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in NU200-series | 15 mm |
| Largest outer diameter in NU200-series | 580 mm |
| Width range across NU200-series | 11–92 mm |
| Bore position in NU200-series (smallest first) | 9 of 36 |
| Bore above smallest NU200-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU210-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 50×90×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 6210 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| 6210-2RS | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| 6210-ZZ | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Identical envelope but a different bearing type — confirm load and speed suitability before substitution. |
| N210-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF N 210 ECP is a different execution with its own cage/flange configuration. |
| NJ210-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NJ 210 ECP is a different execution with its own cage/flange configuration. |
| NUP210-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NUP 210 ECP is a different execution with its own cage/flange configuration. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the NU210 model number is decoded
For a 50 mm shaft carrying pure radial load, SKF lists NU210 under catalogue execution NU 210 ECP: one open single-row cylindrical roller bearing with polymer cage and separable inner ring. Numbering ties the bearing to its envelope: NU210 means cylindrical-roller type NU, standard series 2, 50 mm bore — which is why the 90×20 mm outline swaps dimensionally with other ISO 15 bearings of the same code. The SKF catalogue adds the ECP suffix for the standard glass-fibre reinforced polyamide cage; ECJ (pressed steel) and ECM (machined brass) are alternative executions with different speed and temperature ratings. With C 73.5 kN and C0 69.5 kN, the NU210 radial-capacity check is straightforward: keep the equivalent load P below the rating at the required L10; axial load is not supported by the NU design. Fit selection follows the rotating ring — interference on a rotating inner ring — and the outer ring is free to slide axially in the housing; a 50 mm shaft typically takes a k5 seat with an H7 housing bore.
Typical equipment & failure modes
Common applications
- machine-tool main spindles (radial set)
- paper-machine wet-section rolls
- rolling-mill auxiliary gear trains
- crane hoist and trolley wheel shafts
Known failure patterns
- inner-ring raceway spalling from overload or contamination in the line-contact hertz zone
- outer-ring raceway fatigue after extended service at loads above the catalogue L10 rating
- cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up
- roller-end scoring from inadequate oil flow in the roller-raceway contact
- brinelling from static overload or impact during handling and mounting
Selection pitfalls — read before you substitute
- On this 50 mm bore, thermal expansion of the shaft can preload the inner ring if the fit is too tight; calculate the residual interference at operating temperature and confirm the outer ring can still slide axially in the housing.
- The NU200 series at 50 mm bore (90×20 mm) is the standard-section cylindrical roller envelope; stepping to a wide-section 22/23 variant changes OD, width and heat generation — it is not a drop-in swap when the housing and speed are fixed.
- Open NU210 units need application-supplied sealing and a defined lubricant supply; the line-contact hertz stress is higher than point contact, so film thickness is the first failure mode when viscosity drops.
- The NU210 shares its ISO 15 envelope with other cylindrical bearings of the same code but is not a drop-in replacement for a ball bearing: it has no axial load capacity in the NU design, and a deep-groove bearing cannot replace its radial-capacity duty.
- The 73.5/69.5 kN ratings are SKF catalogue 17000 values for the ECP polymer-cage execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
- SKF lists several executions of NU210 (ECP polymer cage, ECJ pressed steel, ECM machined brass); they are not interchangeable order numbers — quote the full NU 210 ECP designation when purchasing and match the execution to the speed and temperature requirements.
Frequently asked questions
What are the dimensions and catalogue data of NU210?
The NU 210 ECP is a single-row cylindrical roller bearing with 50 mm bore, 90 mm outer diameter and 20 mm width (1.969 × 3.543 × 0.787 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 73.5 kN, C0 69.5 kN, fatigue load limit Pu 8.8 kN, reference speed 8,500 r/min, limiting speed 9,000 r/min, mass about 470 g. It is an open, separable bearing with a glass-fibre reinforced polyamide cage.
How does the NU210 bore code work?
The last two digits of NU210 are bore code 10, so 10 × 5 = 50 mm bore. The 90 mm OD and 20 mm width come from the ISO 15 dimension-series plan, shared with other cylindrical bearings of the same code.
What does the ECP suffix mean on NU210?
ECP stands for a glass-fibre reinforced polyamide cage (PA66), the SKF standard for this size. Alternative executions include ECJ (pressed steel cage) and ECM (machined brass cage), which have different speed and temperature ratings and are separate order numbers.
Can NU210 take axial load?
No — the NU design has no ribs on the outer ring and cannot support axial load in either direction. It is intended for pure radial load with axial location provided by adjacent components. If axial location is required, consider NJ (one-direction) or NUP (two-direction) variants, or pair the NU bearing with a thrust or angular-contact bearing.
How does NU210 compare with a ball bearing of the same bore?
A cylindrical roller bearing has line contact and much higher radial capacity than a ball bearing of the same bore, but it cannot take axial load in the NU design and is sensitive to misalignment (≈ 3–4 minutes of arc). Speed limits are generally lower than deep-groove ball bearings. A ball bearing cannot be dropped into a pure radial cylindrical-roller position without re-checking life and deflection, and vice versa.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 6.1 single-row cylindrical roller bearings on 2026-09-26. Read our editorial & correction policy.