NU2311 bearing: complete specifications & equivalents

Specification table

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.

Cross references & equivalents

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 NU2311 model number is decoded

The NU 2311 ECP is a 55×120×43 mm single-row cylindrical roller bearing — the wide entry in the NU2300 series, with separable inner ring and roller assembly for easy mounting. On the SKF nameplate, NU2311 follows the ISO 15 convention: NU for the separable-inner-ring type, 23 for the wide, final digits 11 for the 55 mm bore. The SKF catalogue adds the ECP suffix for the standard glass-fibre reinforced polyamide cage; ECJ (pressed steel) and ECM (machined brass) are alternative executions with different speed and temperature ratings. The 32.5 mm radial section height ((120−55)/2) and 2250 g catalogue mass frame a 55 mm bore bearing rated at 232 kN C — roughly 4.22 kN of dynamic capacity per millimetre of bore before application factors. The outer ring has no ribs and cannot locate the shaft axially; pair NU2311 with a locating bearing (e.g. deep-groove ball or angular contact) or use an NJ/NUP variant if one-direction location is required.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 55 mm bore, thermal expansion of the shaft can preload the inner ring if the fit is too tight; calculate the residual interference at operating temperature and confirm the outer ring can still slide axially in the housing.
• The NU2300 series at 55 mm bore (120×43 mm) is the wide-section cylindrical roller with higher capacity but lower speed limit than the standard NU300 counterpart; do not substitute without re-checking shaft shoulder diameters and dn limit.
• The NU2311 shares its ISO 15 envelope with other cylindrical bearings of the same code but is not a drop-in replacement for a ball bearing: it has no axial load capacity in the NU design, and a deep-groove bearing cannot replace its radial-capacity duty.
• Open NU2311 units need application-supplied sealing and a defined lubricant supply; the line-contact hertz stress is higher than point contact, so film thickness is the first failure mode when viscosity drops.
• The 232/232 kN ratings are SKF catalogue 17000 values for the ECP polymer-cage execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
• SKF lists several executions of NU2311 (ECP polymer cage, ECJ pressed steel, ECM machined brass); they are not interchangeable order numbers — quote the full NU 2311 ECP designation when purchasing and match the execution to the speed and temperature requirements.