NJ2318E bearing: complete specifications & equivalents
The NJ2318E is a ISO 15 radial bearing sized 90 x 190 x 64 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 90 mm |
| Outer diameter D | 190 mm |
| Width B | 64 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 485 kN |
| Basic static load rating C0 | 535 kN |
| Fatigue load limit Pu | 58.5 kN |
| Limiting speed (mechanical) | 2900 rpm |
| Operating temperature | -40 to +120 °C |
| Manufacturer designation | NTN NJ2318E |
| 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 & NJ2300-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 7.48 in |
| Width B | 2.52 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 50 mm |
| Smallest bore in NJ2300-series | 20 mm |
| Largest outer diameter in NJ2300-series | 580 mm |
| Width range across NJ2300-series | 21–175 mm |
| Bore position in NJ2300-series (smallest first) | 15 of 31 |
| Bore above smallest NJ2300-series size | 70 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ2318E | 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 NJ2318E model number is decoded
NJ2318E is the extra-wide (23) section of the NTN NJ2300 dimension series for a 90 mm shaft — 485 kN of basic dynamic capacity in a open bearing. The leading NJ defines the rib arrangement (inner ring two ribs + one outer rib); the dimension-series digits and the two-digit bore code resolve to 90 mm, with 190 mm OD and 64 mm width from the ISO 15 general plan. NTN ships these bearings open with normal (CN) radial clearance and P0 tolerance as standard; precision classes and C3/C4 clearance are separate order suffixes, not part of NJ2318E. Selection arithmetic: Pu 58.5 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 1.10 (535/485 kN) shows the high-static-capacity proportioning of this 90 mm bore. Heat the inner ring to max 120 °C for the 90 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
- large electric-motor and generator rotors
- cement and mining conveyor drive pulleys
- heavy industrial gearbox and reducer shafts
- large pump, turbine and compressor rotors
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- rolling-contact fatigue after the catalogue L10 life is exceeded
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- Induction-heat the 90 mm inner ring (max 120 °C) and mount it before fitting the outer ring; the ring mass makes square guidance essential — driving through the rollers brinells the 190 mm raceway.
- The 64 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 90 mm inner ring.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NJ2318E skids at 2,900 r/min and fails by smearing long before L10 fatigue.
- If the shaft must be located both ways, do not use NJ2318E alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 190 mm race brinells and releases as vibration within hours.
- The 485/535 kN ratings, 58.5 kN Pu are NTN Ball and Roller Bearings CAT.No.2203E values for NJ2318E (E high-capacity 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 NJ2318E?
NJ2318E is an NTN NJ single-row cylindrical roller bearing to ISO 15: 90 mm bore, 190 mm OD and 64 mm width (3.543 × 7.48 × 2.52 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 485 kN, C0 535 kN, Pu 58.5 kN, grease limiting speed 2,900 r/min, oil 3,400 r/min. It is open, with the high-capacity pressed-steel cage of the E execution.
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. NJ2318E 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. NJ2318E is supplied in the standard open execution shown in the table.
Can NJ2318E 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 NJ2318E?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 113.5 mm. The nominal bore/OD remain 90/190 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,900 r/min grease / 3,400 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.