NJ2224-ECJ bearing: complete specifications & equivalents
The NJ2224-ECJ is a ISO 15 radial bearing sized 120 x 215 x 58 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 120 mm |
| Outer diameter D | 215 mm |
| Width B | 58 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 520 kN |
| Basic static load rating C0 | 630 kN |
| Fatigue load limit Pu | 72 kN |
| Reference speed (thermal) | 3400 rpm |
| Limiting speed (mechanical) | 3600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 8650 g |
| Manufacturer designation | SKF NJ 2224 ECJ |
| 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 | 4.724 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 2.283 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 47.5 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) | 20 of 31 |
| Bore above smallest NJ2200-series size | 103 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU2224-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 120×215×58 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NUP2224-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 120×215×58 mm and equivalent catalogue ratings; the NUP 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 NJ2224-ECJ model number is decoded
For a 120 mm shaft, SKF lists NJ2224-ECJ as single-row caged cylindrical roller: 215 mm OD, 58 mm wide, Pu 72 kN, the catalogue lists 3,400 r/min thermal reference speed and 3,600 r/min mechanical limiting speed. 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 ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. Load-per-bore for the 120 mm seat is about 4.33 kN/mm, typical of dimension series 22 (light-section, wide); use C0 630 kN for static checks such as crane hook blocks standing under load. Fit practice for NJ2224-ECJ: 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. Single-row cylindrical rollers tolerate only about 3–4 minutes of arc misalignment, so verify shaft and housing alignment.
Typical equipment & failure modes
Common applications
- offshore drawworks shafts
- large rolling-mill drive trains
- marine propulsion line shafts
- heavy turbogenerator rotor supports
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
- electrical pitting on VFD-driven shafts without grounding protection
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 2224, but flange configuration and axial-locating behaviour differ — quote the full SKF NJ 2224 ECJ 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 58 mm-wide ring and concentrates load.
- The 520/630 kN ratings are SKF catalogue 17000 (2018) values for the ECJ 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 NJ2224-ECJ?
SKF NJ 2224 ECJ is a single-row caged cylindrical roller bearing with 120 mm bore, 215 mm OD and 58 mm width per ISO 15. SKF lists C 520 kN, C0 630 kN, Pu 72 kN, reference speed 3,400 r/min and limiting speed 3,600 r/min, mass about 8650 g.
What does the NJ designation and ECJ suffix mean?
The ECJ suffix marks the E-design execution with a pressed sheet-steel window cage, useful where polymer cages are temperature- or lubricant-limited. 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 NJ2224-ECJ 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 NJ2224-ECJ 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.