NJ2234-ECML bearing: complete specifications & equivalents
The NJ2234-ECML is a ISO 15 radial bearing sized 170 x 310 x 86 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 170 mm |
| Outer diameter D | 310 mm |
| Width B | 86 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 1060 kN |
| Basic static load rating C0 | 1340 kN |
| Fatigue load limit Pu | 140 kN |
| Reference speed (thermal) | 2200 rpm |
| Limiting speed (mechanical) | 3800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 29000 g |
| Manufacturer designation | SKF NJ 2234 ECML |
| 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 & NJ2200-series range
| Bore d | 6.693 in |
|---|---|
| Outer diameter D | 12.205 in |
| Width B | 3.386 in |
| ISO bore code | 34 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in NJ2200-series | 17 mm |
| Largest outer diameter in NJ2200-series | 480 mm |
| Width range across NJ2200-series | 16–130 mm |
| Bore position in NJ2200-series (smallest first) | 25 of 31 |
| Bore above smallest NJ2200-series size | 153 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU2234-ECML | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 170×310×86 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
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 NJ2234-ECML model number is decoded
In SKF catalogue PUB BU/P1 17000, SKF NJ 2234 ECML denotes a single-row caged cylindrical roller bearing on the ISO 15 170×310×86 mm envelope, dimension series 22 (light-section, wide), with catalogue mass 29000 g. Structurally, the NJ design has two integral flanges on the inner ring and no flanges on the outer ring; the inner ring retains the roller set. In arrangement terms it is able to locate the shaft axially in one direction; an HJ angle ring on the opposite side converts it into two-direction location. The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. The one-piece machined brass cage is reflected in the published speeds and temperature limits. With C 1060 kN and C0 1340 kN, size the bearing on the 170×310 mm ISO 15 envelope and check the 140 kN Pu against the equivalent-load floor; the catalogue lists 2,200 r/min thermal reference speed and 3,800 r/min mechanical limiting speed. Mounting: orient the inner-ring flange side toward the axial load direction; if an HJ angle ring is used, verify its fit and clearance before locking the arrangement. A 170 mm seat normally takes a m6 interference with an H6 housing bore when the inner ring rotates.
Typical equipment & failure modes
Common applications
- heavy turbogenerator rotor supports
- mining hoist and winder shafts
- offshore drawworks shafts
- large rolling-mill drive trains
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 skew at light load
- cage pocket wear from roller skidding at insufficient radial load or during start-up before oil film build-up
- surface distress (micro-pitting) when the EHL film falls below the composite roughness at high specific load
- edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit
- hard-particle indentation of the raceway in unfiltered oil systems
Selection pitfalls — read before you substitute
- Do not use a NJ bearing where two-direction axial location is required without an HJ angle ring
- The dimension series 22 (light-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2234, but flange configuration and axial-locating behaviour differ — quote the full SKF NJ 2234 ECML and do not substitute rib styles without checking the shaft locating scheme.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 86 mm-wide ring and concentrates load.
- The 1060/1340 kN ratings are SKF catalogue 17000 (2018) values for the ECML execution; re-verify against the current catalogue for critical drives and keep the catalogue version with the specification.
Frequently asked questions
What are the dimensions and catalogue data of NJ2234-ECML?
SKF NJ 2234 ECML is a single-row caged cylindrical roller bearing with 170 mm bore, 310 mm OD and 86 mm width per ISO 15. SKF lists C 1060 kN, C0 1340 kN, Pu 140 kN, reference speed 2,200 r/min and limiting speed 3,800 r/min, mass about 29000 g.
What does the NJ designation and ECML suffix mean?
The ECML suffix denotes the E-design execution with a one-piece machined brass cage for higher-temperature and higher-speed continuous duty. Structurally this execution has two integral flanges on the inner ring and no flanges on the outer ring; the inner ring retains the roller set.
Can NJ2234-ECML take axial load and locate the shaft?
In one direction only, via the two inner-ring flanges. Add an HJ angle ring on the opposite side for two-direction location.
How does NJ2234-ECML compare with the other executions in the same envelope?
The N/NU/NJ/NUP executions share the ISO 15 envelope and load ratings but differ in flange arrangement and axial-locating behaviour; quote the exact order number.
What limits the service life of this bearing most often?
Line-contact fatigue above the L10 rating, cage wear at light loads and high temperatures, and edge loading from misalignment beyond about 3–4 minutes of arc are the typical failure drivers.
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.