NU2307 bearing: complete specifications & equivalents
The NU2307 is a ISO 15 radial bearing sized 35 x 80 x 31 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 35 mm |
| Outer diameter D | 80 mm |
| Width B | 31 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 106 kN |
| Basic static load rating C0 | 98 kN |
| Fatigue load limit Pu | 12.7 kN |
| Reference speed (thermal) | 9500 rpm |
| Limiting speed (mechanical) | 11000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 720 g |
| Manufacturer designation | NU 2307 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 | 1.378 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 1.22 in |
| ISO bore code | 07 |
| Radial section height (D−d)/2 | 22.5 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) | 4 of 35 |
| Bore above smallest NU2300-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ2307-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NJ 2307 ECP is a different execution with its own cage/flange configuration. |
| NUP2307-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NUP 2307 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 NU2307 model number is decoded
For a 35 mm shaft carrying pure radial load, SKF lists NU2307 under catalogue execution NU 2307 ECP: one open single-row cylindrical roller bearing with polymer cage and separable inner ring. Numbering ties the bearing to its envelope: NU2307 means cylindrical-roller type NU, wide series 23, 35 mm bore — which is why the 80×31 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. At 9,500 r/min reference speed the 22.5 mm-section NU2307 is governed thermally by cage material and lubricant flow; oil or grease selection should be made against that value, with 11,000 r/min as the mechanical ceiling. The outer ring has no ribs and cannot locate the shaft axially; pair NU2307 with a locating bearing (e.g. deep-groove ball or angular contact) or use an NJ/NUP variant if one-direction location is required.
Typical equipment & failure modes
Common applications
- crane hoist and trolley wheel shafts
- industrial gearbox input/output shafts
- pump and compressor drive shafts
- electric-motor shafts in pumps and fans
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
- edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)
Selection pitfalls — read before you substitute
- On this 35 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 35 mm bore (80×31 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.
- Catalogue reference speed and limiting speed are different limits: the 9,500 r/min reference is a thermal criterion under load, while the 11,000 r/min limiting value is the mechanical ceiling — observe both.
- Never press the outer ring through the roller complement during fitting: force for a press fit goes through the ring faces only, or brinell marks on the 80 mm race release as noise within the first running hours.
- The 106/98 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 NU2307 (ECP polymer cage, ECJ pressed steel, ECM machined brass); they are not interchangeable order numbers — quote the full NU 2307 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 NU2307?
The NU 2307 ECP is a single-row cylindrical roller bearing with 35 mm bore, 80 mm outer diameter and 31 mm width (1.378 × 3.15 × 1.22 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 106 kN, C0 98 kN, fatigue load limit Pu 12.7 kN, reference speed 9,500 r/min, limiting speed 11,000 r/min, mass about 720 g. It is an open, separable bearing with a glass-fibre reinforced polyamide cage.
How does the NU2307 bore code work?
The last two digits of NU2307 are bore code 07, so 07 × 5 = 35 mm bore. The 80 mm OD and 31 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 NU2307?
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 NU2307 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 NU2307 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.