NU314 bearing: complete specifications & equivalents
The NU314 is a ISO 15 radial bearing sized 70 x 150 x 35 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 70 mm |
| Outer diameter D | 150 mm |
| Width B | 35 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 236 kN |
| Basic static load rating C0 | 228 kN |
| Fatigue load limit Pu | 29 kN |
| Reference speed (thermal) | 4800 rpm |
| Limiting speed (mechanical) | 5600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2700 g |
| Manufacturer designation | NU 314 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 & NU300-series range
| Bore d | 2.756 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 1.378 in |
| ISO bore code | 14 |
| Radial section height (D−d)/2 | 40 mm |
| Smallest bore in NU300-series | 17 mm |
| Largest outer diameter in NU300-series | 620 mm |
| Width range across NU300-series | 14–109 mm |
| Bore position in NU300-series (smallest first) | 12 of 34 |
| Bore above smallest NU300-series size | 53 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU314-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 70×150×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 6314 | 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. |
| 6314-2RS | 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. |
| 6314-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. |
| N314-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF N 314 ECP is a different execution with its own cage/flange configuration. |
| NJ314-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NJ 314 ECP is a different execution with its own cage/flange configuration. |
| NUP314-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 boundary envelope and equivalent catalogue ratings; SKF NUP 314 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 NU314 model number is decoded
NU 314 ECP belongs to the SKF single-row cylindrical roller range — the 70 mm bore entry in the NU300 series, dimensioned 150 mm OD and 35 mm wide to the ISO 15 boundary plan. Reading the designation: the leading NU marks a single-row cylindrical roller bearing with separable inner ring, the 3 is the ISO 15 diameter/width series (standard), and the last two digits encode the 70 mm bore; the 150 mm OD and 35 mm width follow the ISO 15 general plan. 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 236 kN and C0 228 kN, the NU314 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. Mount the separable inner ring + roller assembly onto the shaft first, then slide the outer ring into the housing; the NU design has no outer-ring ribs, so axial location of the shaft must be provided by adjacent components or a second bearing.
Typical equipment & failure modes
Common applications
- paper-machine dryer and calender rolls
- cement-kiln support-roller shafts
- wind-turbine gearbox intermediate shafts
- marine propulsion gearbox 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
- polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant
- surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load
- 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
- Mount the 70 mm bore NU314 by induction heating of the inner ring (max 120 °C — the polymer cage sets the ceiling, not the steel); driving it home through the rollers brinells the raceway.
- The NU300 series at 70 mm bore (150×35 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.
- 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 NU314 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 236/228 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 NU314 (ECP polymer cage, ECJ pressed steel, ECM machined brass); they are not interchangeable order numbers — quote the full NU 314 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 NU314?
The NU 314 ECP is a single-row cylindrical roller bearing with 70 mm bore, 150 mm outer diameter and 35 mm width (2.756 × 5.906 × 1.378 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 236 kN, C0 228 kN, fatigue load limit Pu 29 kN, reference speed 4,800 r/min, limiting speed 5,600 r/min, mass about 2700 g. It is an open, separable bearing with a glass-fibre reinforced polyamide cage.
How does the NU314 bore code work?
The last two digits of NU314 are bore code 14, so 14 × 5 = 70 mm bore. The 150 mm OD and 35 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 NU314?
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 NU314 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 NU314 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.