NUP309 bearing: complete specifications & equivalents
The NUP309 is a ISO 15 radial bearing sized 45 x 100 x 25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 45 mm |
| Outer diameter D | 100 mm |
| Width B | 25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 82 kN |
| Basic static load rating C0 | 71 kN |
| Fatigue load limit Pu | 8.65 kN |
| Limiting speed (mechanical) | 7200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 857 g |
| Manufacturer designation | NTN NUP309 |
| 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 & NUP300-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 0.984 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in NUP300-series | 20 mm |
| Largest outer diameter in NUP300-series | 580 mm |
| Width range across NUP300-series | 15–108 mm |
| Bore position in NUP300-series (smallest first) | 6 of 32 |
| Bore above smallest NUP300-series size | 25 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NUP309-ECP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×100×25 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 NUP309 model number is decoded
NTN lists NUP309 on the 45×100 mm envelope, 25 mm wide: a line-contact radial bearing with a pressed sheet-steel cage and a grease limiting speed of 7,200 r/min. On the NTN nameplate NUP states which ring carries the ribs, which determines whether NUP309 floats or locates; the numeric remainder is the ISO 15 series and 45 mm bore reference, not a fit or clearance instruction. Minimum radial load matters: an unloaded NUP309 at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Thermal planning around the 7,200 r/min grease ceiling should include the cage type (a pressed sheet-steel cage) and oil-flow option to 8,400 r/min for continuously high-duty 45 mm positions. Heat the inner ring to max 120 °C for the 45 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
- material-handling drum and wheel shafts
- papermaking and printing auxiliary drives
- fan and blower rotor positions
- industrial gearbox input and output shafts
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- electrical pitting on VFD-driven motor shafts without grounding protection
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- On this 45 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 NUP309.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 100 mm race brinells and releases as vibration within hours.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 100 mm race brinells and releases as vibration within hours.
- Open NUP309 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 45 mm contact.
- Do not replace NUP309 with a deep-groove ball bearing on rating alone: line contact gives 82 kN radial capacity but the bearing only accepts small sustained axial guidance loads and misalignment tolerance is only 3–4 arc-minutes.
- The 82/71 kN ratings, 8.65 kN Pu and 857 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NUP309 (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 NUP309?
NUP309 is an NTN NUP single-row cylindrical roller bearing to ISO 15: 45 mm bore, 100 mm OD and 25 mm width (1.772 × 3.937 × 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 82 kN, C0 71 kN, Pu 8.65 kN, grease limiting speed 7,200 r/min, oil 8,400 r/min, mass about 857 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. NUP309 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. NUP309 is listed among the ＊ ULTAGE-marked executions in 2203E.
Can NUP309 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 NUP309?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 58.5 mm, Ew 86.5 mm. The nominal bore/OD remain 45/100 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 7,200 r/min grease / 8,400 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.