NJ208EA bearing: complete specifications & equivalents
The NJ208EA is a ISO 15 radial bearing sized 40 x 80 x 18 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 | 80 mm |
| Width B | 18 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 66 kN |
| Basic static load rating C0 | 55.5 kN |
| Fatigue load limit Pu | 6.75 kN |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 365 g |
| Manufacturer designation | NTN NJ208EA |
| 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 & NJ200-series range
| Bore d | 1.575 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 0.709 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in NJ200-series | 15 mm |
| Largest outer diameter in NJ200-series | 580 mm |
| Width range across NJ200-series | 11–92 mm |
| Bore position in NJ200-series (smallest first) | 7 of 36 |
| Bore above smallest NJ200-series size | 25 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ208EA | 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 NJ208EA model number is decoded
For pure radial duty on a 40 mm shaft NTN supplies NJ208EA: two integral ribs on the inner ring and one rib on the outer ring; the open execution is rated 8,500 r/min on grease and 12,000 r/min on oil. On the NTN nameplate NJ states which ring carries the ribs, which determines whether NJ208EA floats or locates; the numeric remainder is the ISO 15 series and 40 mm bore reference, not a fit or clearance instruction. The 20.0 mm radial section ((80−40)/2) frames the roller complement; capacity per millimetre of bore is about 1.6 kN/mm before application factors. Rating life at 66 kN C assumes clean oil and adequate film; the 6.75 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. The NJ design locates in one direction only: for two-direction location fit the matching loose rib ring (NUP execution) or pair the bearings back to back on the 40 mm shaft.
Typical equipment & failure modes
Common applications
- fan and blower rotor positions
- industrial gearbox input and output shafts
- medium electric-motor and generator shafts
- pump and compressor crankshafts and rotors
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
- rolling-contact fatigue after the catalogue L10 life is exceeded
- electrical pitting on VFD-driven motor shafts without grounding protection
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 NJ208EA.
- Grease limiting speed 8,500 r/min and oil 12,000 r/min are different limits for NJ208EA: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- If the shaft must be located both ways, do not use NJ208EA alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 20.0 mm section at 40 mm bore leaves a narrow oil path; with the EA pressed-steel-cage cage the relubrication groove and oil-level design must keep grease from churning in the 18 mm-wide cavity.
- The 20.0 mm section at 40 mm bore leaves a narrow oil path; with the EA pressed-steel-cage cage the relubrication groove and oil-level design must keep grease from churning in the 18 mm-wide cavity.
- The 66/55.5 kN ratings, 6.75 kN Pu and 365 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ208EA (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 NJ208EA?
NJ208EA is an NTN NJ single-row cylindrical roller bearing to ISO 15: 40 mm bore, 80 mm OD and 18 mm width (1.575 × 3.15 × 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 66 kN, C0 55.5 kN, Pu 6.75 kN, grease limiting speed 8,500 r/min, oil 12,000 r/min, mass about 365 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. NJ208EA 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 NJ208EA 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 NJ208EA?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 49.5 mm, Ew 71.5 mm. The nominal bore/OD remain 40/80 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 8,500 r/min grease / 12,000 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.