NUP2311-ECP bearing: complete specifications & equivalents
The NUP2311-ECP is a ISO 15 radial bearing sized 55 x 120 x 43 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 | 120 mm |
| Width B | 43 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | polymer (PA66 glass-fibre reinforced) |
| Basic dynamic load rating C | 232 kN |
| Basic static load rating C0 | 232 kN |
| Fatigue load limit Pu | 30.5 kN |
| Reference speed (thermal) | 6000 rpm |
| Limiting speed (mechanical) | 7000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2300 g |
| Manufacturer designation | SKF NUP 2311 ECP |
| 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 & NUP2300-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 4.724 in |
| Width B | 1.693 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 32.5 mm |
| Smallest bore in NUP2300-series | 20 mm |
| Largest outer diameter in NUP2300-series | 300 mm |
| Width range across NUP2300-series | 21–102 mm |
| Bore position in NUP2300-series (smallest first) | 8 of 21 |
| Bore above smallest NUP2300-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ2311-ECP | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 55×120×43 mm and equivalent catalogue ratings; the NJ execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NU2311 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 55×120×43 mm and equivalent catalogue ratings; the NU execution differs in flange/retaining-ring configuration — boundary-dimension interchangeable, but axial-locating behaviour is not identical. |
| NU2311 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same ISO 15 envelope 55×120×43 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 NUP2311-ECP model number is decoded
SKF NUP 2311 ECP is a single-row caged cylindrical roller bearing sized 55×120×43 mm — a dimension series 23 (medium-section, wide), listed in SKF catalogue PUB BU/P1 17000 ch. 6.1. The NUP configuration means two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring; functionally the bearing is a locating bearing that positions the shaft axially in both directions while keeping the cylindrical-roller radial capacity. The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. The glass-fibre reinforced polyamide (PA66) window-type cage is reflected in the published speeds and temperature limits. The radial section height is 32.5 mm and the catalogue mass 2300 g; at 232 kN dynamic rating this is roughly 4.22 kN of C per millimetre of bore before application factors. Fit practice for NUP2311-ECP: the loose inner-ring flange must be fitted on the correct side and retained by the shaft abutment; never omit it during reassembly or the bearing loses its two-direction locating function. 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
- electric-motor shafts in pumps and fans
- compressor crank and rotor shafts
- machine-tool radial spindle supports
- conveyor drive-pulley 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
- polymer cage softening above 120 °C
- 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
- edge loading from shaft deflection beyond the bearing alignment limit (≈ 3-4 minutes of arc for single-row CRB)
Selection pitfalls — read before you substitute
- Do not use a NUP bearing where a floating non-locating bearing is required — the loose inner flange makes it a locating bearing
- The dimension series 23 (medium-section, wide) envelope is shared with the N/NU/NJ/NUP executions of 2311, but flange configuration and axial-locating behaviour differ — quote the full SKF NUP 2311 ECP 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 120 mm raceway.
- Catalogue reference and limiting speeds are different criteria: observe the mechanical ceiling even when thermal calculations allow more.
- The 232/232 kN ratings are SKF catalogue 17000 (2018) values for the ECP 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 NUP2311-ECP?
SKF NUP 2311 ECP is a single-row caged cylindrical roller bearing with 55 mm bore, 120 mm OD and 43 mm width per ISO 15. SKF lists C 232 kN, C0 232 kN, Pu 30.5 kN, reference speed 6,000 r/min and limiting speed 7,000 r/min, mass about 2300 g.
What does the NUP designation and ECP suffix mean?
The ECP suffix marks the E-design execution with a glass-fibre reinforced polyamide (PA66) cage, limited to 120 °C continuous. Structurally this execution has two integral flanges on the outer ring plus one integral flange and one loose flange ring on the inner ring.
Can NUP2311-ECP take axial load and locate the shaft?
Yes, in both directions: the integral inner flange plus the loose flange ring close both axial paths. Do not pair it with another locating bearing without thermal clearance.
How does NUP2311-ECP 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.