NUP2308 bearing: complete specifications & equivalents
The NUP2308 is a ISO 15 radial bearing sized 40 x 90 x 33 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 40 mm |
| Outer diameter D | 90 mm |
| Width B | 33 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 91.5 kN |
| Basic static load rating C0 | 88 kN |
| Fatigue load limit Pu | 10.7 kN |
| Limiting speed (mechanical) | 7000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 932 g |
| Manufacturer designation | NTN NUP2308 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & NUP2300-series range
| Bore d | 1.575 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 1.299 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in NUP2300-series | 20 mm |
| Largest outer diameter in NUP2300-series | 580 mm |
| Width range across NUP2300-series | 21–175 mm |
| Bore position in NUP2300-series (smallest first) | 5 of 31 |
| Bore above smallest NUP2300-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NUP2308-ECP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×90×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 NUP2308 model number is decoded
NUP2308 is an NTN NUP cylindrical roller bearing: the NJ rib arrangement plus a loose L-shaped rib ring on the inner ring — it locates the shaft in both axial directions, inside the 40×90×33 mm ISO 15 envelope. Numbering ties NUP2308 to its envelope: type code NUP, series NUP2300, 40 mm bore; the 90×33 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. The 25.0 mm radial section ((90−40)/2) frames the roller complement; capacity per millimetre of bore is about 2.3 kN/mm before application factors. Mass 932 g for the 40×90×33 mm NUP2308 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. Heat the inner ring to max 120 °C for the 40 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.
Typical equipment & failure modes
Common applications
- industrial gearbox input and output shafts
- medium electric-motor and generator shafts
- pump and compressor crankshafts and rotors
- machine-tool gearbox and spindle radial sets
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- cage distortion after a mounting blow carried through the roller set
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- hard-particle indentation of raceways in unfiltered oil or open arrangements
Selection pitfalls — read before you substitute
- On this 40 mm bore, shaft thermal growth can preload the inner ring if the fit is too tight; verify residual interference at temperature and confirm the float ring still slides after mounting NUP2308.
- If the shaft must be located both ways, do not use NUP2308 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Do not replace NUP2308 with a deep-groove ball bearing on rating alone: line contact gives 91.5 kN radial capacity but the bearing only accepts small sustained axial guidance loads and misalignment tolerance is only 3–4 arc-minutes.
- Open NUP2308 units need application-supplied sealing and a defined lubricant schedule; film thickness is the first failure mode for line contact when viscosity drops at the 40 mm contact.
- The 25.0 mm section at 40 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 33 mm-wide cavity.
- The 91.5/88 kN ratings, 10.7 kN Pu and 932 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NUP2308 (standard execution); other makes sharing the ISO 15 envelope revise internal geometry without changing the order number, so keep the 2203E reference with the specification for critical drives.
Frequently asked questions
What are the dimensions and catalogue data of NUP2308?
NUP2308 is an NTN NUP single-row cylindrical roller bearing to ISO 15: 40 mm bore, 90 mm OD and 33 mm width (1.575 × 3.543 × 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 91.5 kN, C0 88 kN, Pu 10.7 kN, grease limiting speed 7,000 r/min, oil 8,200 r/min, mass about 932 g. It is open, with a pressed sheet-steel cage.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
The prefix states the rib arrangement: NU has two outer-ring ribs and a ribless inner ring (float, no axial load); NJ adds ribs for one-direction location; NUP adds a loose L-ring to locate both directions; N has two inner-ring ribs and a separable outer ring; NF has one rib per ring for one-direction guidance. NUP2308 is the NJ rib arrangement plus a loose L-shaped rib ring on the inner ring — it locates the shaft in both axial directions.
What do the EA, E and ＊ suffixes mean on NTN cylindrical roller bearings?
EA is NTN's high-capacity design with a pressed sheet-steel cage and optimised roller complement in the same ISO 15 envelope; E marks the high-capacity design at the larger bores; the ＊ symbol printed before the code in the NTN catalogue marks the ULTAGE new-generation specification and is not typed as part of the order number. NUP2308 is listed among the ＊ ULTAGE-marked executions in 2203E.
Can NUP2308 take axial load and locate a shaft?
the NUP design provides two-direction axial location via its loose rib ring, for light/moderate thrust guidance. The loose rib ring still only suits light/short-duration axial guidance; heavy thrust belongs to a dedicated thrust bearing.
What do Fw and Ew mean for NUP2308?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 53.5 mm, Ew 77.5 mm. The nominal bore/OD remain 40/90 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 7,000 r/min grease / 8,200 r/min oil.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.