NJ318E bearing: complete specifications & equivalents
The NJ318E is a ISO 15 radial bearing sized 90 x 190 x 43 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 | 43 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 350 kN |
| Basic static load rating C0 | 355 kN |
| Fatigue load limit Pu | 39 kN |
| Limiting speed (mechanical) | 3300 rpm |
| Operating temperature | -40 to +120 °C |
| Manufacturer designation | NTN NJ318E |
| 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 | 3.543 in |
|---|---|
| Outer diameter D | 7.48 in |
| Width B | 1.693 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 50 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) | 16 of 33 |
| Bore above smallest NJ300-series size | 73 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ318E | 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 NJ318E model number is decoded
The NTN order number NJ318E denotes a 90×190×43 mm (3.543 × 7.48 × 1.693 in) cylindrical roller bearing in the NJ300 family, the high-capacity pressed-steel cage of the E execution. Numbering ties NJ318E to its envelope: type code NJ, series NJ300, 90 mm bore; the 190×43 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 NJ318E 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 3,300 r/min grease ceiling should include the cage type (the high-capacity pressed-steel cage of the E execution) and oil-flow option to 3,900 r/min for continuously high-duty 90 mm positions. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of NJ318E.
Typical equipment & failure modes
Common applications
- heavy industrial gearbox and reducer shafts
- large pump, turbine and compressor rotors
- rolling-mill auxiliary drive shafts
- crusher and vibrating-screen drive shafts
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
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- fretting corrosion on a loose rotating shaft seat
- rolling-contact fatigue after the catalogue L10 life is exceeded
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.
- If the shaft must be located both ways, do not use NJ318E 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 NJ318E with a deep-groove ball bearing on rating alone: line contact gives 350 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 NJ318E skids at 3,300 r/min and fails by smearing long before L10 fatigue.
- Do not replace NJ318E with a deep-groove ball bearing on rating alone: line contact gives 350 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 350/355 kN ratings, 39 kN Pu are NTN Ball and Roller Bearings CAT.No.2203E values for NJ318E (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 NJ318E?
NJ318E is an NTN NJ single-row cylindrical roller bearing to ISO 15: 90 mm bore, 190 mm OD and 43 mm width (3.543 × 7.48 × 1.693 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 350 kN, C0 355 kN, Pu 39 kN, grease limiting speed 3,300 r/min, oil 3,900 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. NJ318E 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. NJ318E is supplied in the standard open execution shown in the table.
Can NJ318E 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 NJ318E?
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 3,300 r/min grease / 3,900 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.