NU2309 bearing: complete specifications & equivalents
The NU2309 is a ISO 15 radial bearing sized 45 x 100 x 36 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 100 mm |
| Width B | 36 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 160 kN |
| Basic static load rating C0 | 153 kN |
| Fatigue load limit Pu | 20 kN |
| Reference speed (thermal) | 7500 rpm |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1300 g |
| Manufacturer designation | NU 2309 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 & NU2300-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 1.417 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in NU2300-series | 20 mm |
| Largest outer diameter in NU2300-series | 750 mm |
| Width range across NU2300-series | 21–224 mm |
| Bore position in NU2300-series (smallest first) | 6 of 35 |
| Bore above smallest NU2300-series size | 25 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU2309-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×100×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| NJ2309-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NJ 2309 ECP is a different execution with its own cage/flange configuration. |
| NUP2309-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NUP 2309 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 NU2309 model number is decoded
Ordering number NU 2309 ECP in SKF catalogue PUB BU/P1 17000 denotes a single-row cylindrical roller bearing for a 45 mm shaft, wide section, with an open polymer-cage execution and separable inner ring assembly. The code breaks down as type prefix NU (inner ring separable, no outer-ring ribs), series 23 (the wide), and bore code 09 = 45 mm; dimensions 45×100×36 mm therefore match the ISO 15 envelope. 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 160 kN and C0 153 kN, the NU2309 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. For a 45 mm shaft the usual inner-ring seat is k5 with an H7 housing when the inner ring rotates; the outer ring slides axially to accommodate thermal expansion of the shaft.
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
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- On this 45 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 NU2300 series at 45 mm bore (100×36 mm) is the wide-section cylindrical roller with higher capacity but lower speed limit than the standard NU300 counterpart; do not substitute without re-checking shaft shoulder diameters and dn limit.
- The ECP polymer cage is rated for standard industrial service up to 120 °C; sustained running above the limiting speed or with degraded lubricant softens the cage — inspect at every relubrication interval.
- Open NU2309 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 160/153 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 NU2309 (ECP polymer cage, ECJ pressed steel, ECM machined brass); they are not interchangeable order numbers — quote the full NU 2309 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 NU2309?
The NU 2309 ECP is a single-row cylindrical roller bearing with 45 mm bore, 100 mm outer diameter and 36 mm width (1.772 × 3.937 × 1.417 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 160 kN, C0 153 kN, fatigue load limit Pu 20 kN, reference speed 7,500 r/min, limiting speed 8,500 r/min, mass about 1300 g. It is an open, separable bearing with a glass-fibre reinforced polyamide cage.
How does the NU2309 bore code work?
The last two digits of NU2309 are bore code 09, so 09 × 5 = 45 mm bore. The 100 mm OD and 36 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 NU2309?
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 NU2309 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 NU2309 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.