NJ1044-ML bearing: complete specifications & equivalents
The NJ1044-ML is a ISO 15 radial bearing sized 220 x 340 x 56 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 220 mm |
| Outer diameter D | 340 mm |
| Width B | 56 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 495 kN |
| Basic static load rating C0 | 735 kN |
| Fatigue load limit Pu | 73.5 kN |
| Reference speed (thermal) | 2200 rpm |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 18500 g |
| Manufacturer designation | SKF NJ 1044 ML |
| 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 & NJ1000-series range
| Bore d | 8.661 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 2.205 in |
| ISO bore code | 44 |
| Radial section height (D−d)/2 | 60 mm |
| Smallest bore in NJ1000-series | 45 mm |
| Largest outer diameter in NJ1000-series | 600 mm |
| Width range across NJ1000-series | 16–90 mm |
| Bore position in NJ1000-series (smallest first) | 10 of 15 |
| Bore above smallest NJ1000-series size | 175 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU1044-ML | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 220×340×56 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 NJ1044-ML model number is decoded
SKF NJ 1044 ML is a single-row caged cylindrical roller bearing sized 220×340×56 mm — a dimension series 10 (extra-slim OD, normal width), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NJ prefix: two integral flanges on the inner ring and no flanges on the outer ring; the inner ring retains the roller set. This makes the execution able to locate the shaft axially in one direction; an HJ angle ring on the opposite side converts it into two-direction location. Reading the order-string suffix ML: the basic (non-E) ML execution with a machined brass cage, standard for the larger and earlier-design sizes. Speed planning for NJ1044-ML: the catalogue lists 2,200 r/min thermal reference speed and 3,200 r/min mechanical limiting speed. The mass entry 18500 g covers the complete catalogue execution. Assembly note: 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. Heat steel rings inductively to max 120 °C.
Typical equipment & failure modes
Common applications
- mining hoist and winder shafts
- offshore drawworks shafts
- large rolling-mill drive trains
- marine propulsion line 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
- cage pocket wear from roller skew at light load
- polymer cage cracking or softening after sustained running above 120 °C or with incompatible lubricant
- roller-end scoring from inadequate oil flow in the roller-raceway contact
- edge-loading fatigue after shaft deflection beyond the 3–4 minute alignment limit
- fretting corrosion on a loose rotating shaft seat or in a vibratory stand-still
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 10 (extra-slim OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 1044, but flange configuration and axial-locating behaviour differ — quote the full SKF NJ 1044 ML and do not substitute rib styles without checking the shaft locating scheme.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 56 mm-wide ring and concentrates load.
- Shaft and housing fillets must clear the bearing chamfers; an oversized radius tilts the 56 mm-wide ring and concentrates load.
- The 495/735 kN ratings are SKF catalogue 17000 (2018) values for the ML 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 NJ1044-ML?
SKF NJ 1044 ML is a single-row caged cylindrical roller bearing with 220 mm bore, 340 mm OD and 56 mm width per ISO 15. SKF lists C 495 kN, C0 735 kN, Pu 73.5 kN, reference speed 2,200 r/min and limiting speed 3,200 r/min, mass about 18500 g.
What does the NJ designation and ML suffix mean?
The ML suffix marks the basic (non-E) execution with a machined brass cage, the standard choice for the larger and earlier-design sizes. 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 NJ1044-ML 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 NJ1044-ML 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.