NJ309EA bearing: complete specifications & equivalents
The NJ309EA 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, stamped ribbon (J-type) |
| Basic dynamic load rating C | 115 kN |
| Basic static load rating C0 | 98.5 kN |
| Fatigue load limit Pu | 12 kN |
| Limiting speed (mechanical) | 6500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 865 g |
| Manufacturer designation | NTN NJ309EA |
| 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 & NJ300-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 0.984 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in NJ300-series | 17 mm |
| Largest outer diameter in NJ300-series | 580 mm |
| Width range across NJ300-series | 14–108 mm |
| Bore position in NJ300-series (smallest first) | 7 of 33 |
| Bore above smallest NJ300-series size | 28 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ309EA | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 NJ309EA model number is decoded
The NTN order number NJ309EA denotes a 45×100×25 mm (1.772 × 3.937 × 0.984 in) cylindrical roller bearing in the NJ300 family, the EA high-capacity pressed sheet-steel cage. Numbering ties NJ309EA to its envelope: type code NJ, series NJ300, 45 mm bore; the 100×25 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. Minimum radial load matters: an unloaded NJ309EA at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Mass 865 g for the 45×100×25 mm NJ309EA execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NJ309EA non-locating position preloads the bearing when the shaft grows.
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
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- false brinelling on standby machines exposed to external vibration
- false brinelling on standby machines exposed to external vibration
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 NJ309EA.
- If the shaft must be located both ways, do not use NJ309EA 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 NJ309EA with a deep-groove ball bearing on rating alone: line contact gives 115 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NJ309EA skids at 6,500 r/min and fails by smearing long before L10 fatigue.
- Do not replace NJ309EA with a deep-groove ball bearing on rating alone: line contact gives 115 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- The 115/98.5 kN ratings, 12 kN Pu and 865 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ309EA (EA pressed-steel-cage 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 NJ309EA?
NJ309EA is an NTN NJ 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 115 kN, C0 98.5 kN, Pu 12 kN, grease limiting speed 6,500 r/min, oil 9,100 r/min, mass about 865 g. It is open, with the EA high-capacity 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. NJ309EA is two integral ribs on the inner ring and one rib on the outer ring — it locates the shaft in one axial direction.
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. This page's bearing carries the EA pressed-steel-cage execution.
Can NJ309EA take axial load and locate a shaft?
the NJ design accepts axial load in one direction and provides one-way shaft location. For two-direction location use an NUP execution or an NJ pair with loose rib rings.
What do Fw and Ew mean for NJ309EA?
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 88.5 mm. The nominal bore/OD remain 45/100 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 6,500 r/min grease / 9,100 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.