NJ320-ECJ bearing: complete specifications & equivalents
The NJ320-ECJ is a ISO 15 radial bearing sized 100 x 215 x 47 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 100 mm |
| Outer diameter D | 215 mm |
| Width B | 47 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 450 kN |
| Basic static load rating C0 | 440 kN |
| Fatigue load limit Pu | 51 kN |
| Reference speed (thermal) | 3200 rpm |
| Limiting speed (mechanical) | 3800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7650 g |
| Manufacturer designation | SKF NJ 320 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 & NJ300-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 1.85 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 57.5 mm |
| Smallest bore in NJ300-series | 17 mm |
| Largest outer diameter in NJ300-series | 500 mm |
| Width range across NJ300-series | 14–95 mm |
| Bore position in NJ300-series (smallest first) | 18 of 29 |
| Bore above smallest NJ300-series size | 83 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N320-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 100×215×47 mm and equivalent catalogue ratings; the N execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NUP320-ECJ | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 100×215×47 mm and equivalent catalogue ratings; the NUP execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NU320 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 100×215×47 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NU320 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 100×215×47 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NU320 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 100×215×47 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 NJ320-ECJ model number is decoded
NJ320-ECJ is the 100 mm bore entry in the NJ300 range: a 100×215×47 mm single-row caged cylindrical roller bearing with a pressed sheet-steel window-type cage, rated C 450 kN / C0 440 kN. The NJ configuration means two integral flanges on the inner ring and no flanges on the outer ring; the inner ring retains the roller set; functionally the bearing 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. The pressed sheet-steel window-type cage is reflected in the published speeds and temperature limits. Selection arithmetic: C0/C ≈ 0.98 (440 against 450 kN), and the Pu figure 51 kN is the fatigue load-limit floor for the SKF life equation; the catalogue lists 3,200 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 100 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.
Typical equipment & failure modes
Common applications
- heavy gearbox and pinion shafts
- large pump and blower rotors
- rolling-mill auxiliary drive shafts
- paper-machine press rolls
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 3 (medium-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 320, but flange configuration and axial-locating behaviour differ — quote the full SKF NJ 320 ECJ and do not substitute rib styles without checking the shaft locating scheme.
- Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 215 mm raceway.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 47 mm-wide ring and concentrates load.
- The 450/440 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 NJ320-ECJ?
SKF NJ 320 ECJ is a single-row caged cylindrical roller bearing with 100 mm bore, 215 mm OD and 47 mm width per ISO 15. SKF lists C 450 kN, C0 440 kN, Pu 51 kN, reference speed 3,200 r/min and limiting speed 3,800 r/min, mass about 7650 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 NJ320-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 NJ320-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.