NU411 bearing: complete specifications & equivalents
The NU411 is a ISO 15 radial bearing sized 55 x 140 x 33 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 55 mm |
| Outer diameter D | 140 mm |
| Width B | 33 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 142 kN |
| Basic static load rating C0 | 140 kN |
| Fatigue load limit Pu | 18.6 kN |
| Reference speed (thermal) | 5600 rpm |
| Limiting speed (mechanical) | 6300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2500 g |
| Manufacturer designation | SKF NU 411 |
| 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 & NU400-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 1.299 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 42.5 mm |
| Smallest bore in NU400-series | 25 mm |
| Largest outer diameter in NU400-series | 310 mm |
| Width range across NU400-series | 21–72 mm |
| Bore position in NU400-series (smallest first) | 7 of 17 |
| Bore above smallest NU400-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU411-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| NJ411 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 55×140×33 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 NU411 model number is decoded
NU411 is the 55 mm bore entry in the NU400 range: a 55×140×33 mm single-row caged cylindrical roller bearing with a pressed sheet-steel window-type cage, rated C 142 kN / C0 140 kN. The NU configuration means 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; functionally the bearing is non-locating: the inner ring assembly can float axially in both directions and the bearing cannot support axial load. The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. Load-per-bore for the 55 mm seat is about 2.58 kN/mm, typical of dimension series 4 (heavy-section ISO 15 envelope); use C0 140 kN for static checks such as crane hook blocks standing under load. Mounting: 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. A 55 mm seat normally takes a k5 interference with an H6 housing bore when the inner ring rotates.
Typical equipment & failure modes
Common applications
- conveyor drive-pulley shafts
- medium industrial gearbox shafts
- electric-motor shafts in pumps and fans
- compressor crank and rotor 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
- 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
- false brinelling on standby machines exposed to external vibration
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 4 (heavy-section ISO 15 envelope) envelope is shared with the N/NU/NJ/NUP executions of 411, but flange configuration and axial-locating behaviour differ — quote the full SKF NU 411 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 140 mm raceway.
- Press-fit force goes through ring faces only; driving a ring home through the rollers brinells the 140 mm raceway.
- The 142/140 kN ratings are SKF catalogue 17000 (2018) values for the basic 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 NU411?
SKF NU 411 is a single-row caged cylindrical roller bearing with 55 mm bore, 140 mm OD and 33 mm width per ISO 15. SKF lists C 142 kN, C0 140 kN, Pu 18.6 kN, reference speed 5,600 r/min and limiting speed 6,300 r/min, mass about 2500 g.
What does the NU designation and plain suffix mean?
The plain designation (no cage suffix) identifies the basic execution supplied with a standard pressed-steel cage. 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 NU411 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 NU411 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.