NU2988-ECML bearing: complete specifications & equivalents
The NU2988-ECML is a ISO 15 radial bearing sized 440 x 600 x 95 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 440 mm |
| Outer diameter D | 600 mm |
| Width B | 95 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 1870 kN |
| Basic static load rating C0 | 3900 kN |
| Fatigue load limit Pu | 340 kN |
| Reference speed (thermal) | 1100 rpm |
| Limiting speed (mechanical) | 1600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 81000 g |
| Manufacturer designation | SKF NU 2988 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 & NU2900-series range
| Bore d | 17.323 in |
|---|---|
| Outer diameter D | 23.622 in |
| Width B | 3.74 in |
| ISO bore code | 88 |
| Radial section height (D−d)/2 | 80 mm |
| Smallest bore in NU2900-series | 420 mm |
| Largest outer diameter in NU2900-series | 1180 mm |
| Width range across NU2900-series | 82–165 mm |
| Bore position in NU2900-series (smallest first) | 2 of 7 |
| Bore above smallest NU2900-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ2988-ECML | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 440×600×95 mm and equivalent catalogue ratings; the NJ 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 NU2988-ECML model number is decoded
SKF NU 2988 ECML is a single-row caged cylindrical roller bearing sized 440×600×95 mm — a dimension series 29 (compact OD, normal width), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. Reading the NU prefix: two integral flanges on the outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable. This makes the execution non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. Reading the order-string suffix ECML: the E-design ECML execution with a one-piece machined brass cage for higher-temperature, higher-speed continuous duty. With C 1870 kN and C0 3900 kN, size the bearing on the 440×600 mm ISO 15 envelope and check the 340 kN Pu against the equivalent-load floor; the catalogue lists 1,100 r/min thermal reference speed and 1,600 r/min mechanical limiting speed. Fit practice for NU2988-ECML: fit the inner ring and roller assembly onto the shaft and the outer ring into the housing independently; thermal expansion is absorbed by axial float, so do not trap the inner ring between shaft shoulders. 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
- 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
- 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 NU bearing where axial load must be carried — the design carries radial load only
- The dimension series 29 (compact OD, normal width) envelope is shared with the N/NU/NJ/NUP executions of 2988, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 2988 ECML 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 95 mm-wide ring and concentrates load.
- Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 600 mm raceway.
- The 1870/3900 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 NU2988-ECML?
SKF NU 2988 ECML is a single-row caged cylindrical roller bearing with 440 mm bore, 600 mm OD and 95 mm width per ISO 15. SKF lists C 1870 kN, C0 3900 kN, Pu 340 kN, reference speed 1,100 r/min and limiting speed 1,600 r/min, mass about 81000 g.
What does the NU 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 outer ring and no flanges on the inner ring, so the inner ring together with the roller set is separable.
Can NU2988-ECML take axial load and locate the shaft?
No — the inner ring has no flanges, so the NU bearing is non-locating and carries radial load only; use NJ (one direction), NUP (both directions) or a paired thrust bearing for axial duty.
How does NU2988-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.