NJ238E bearing: complete specifications & equivalents
The NJ238E is a ISO 15 radial bearing sized 190 x 340 x 55 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 190 mm |
| Outer diameter D | 340 mm |
| Width B | 55 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 770 kN |
| Basic static load rating C0 | 955 kN |
| Fatigue load limit Pu | 86.5 kN |
| Limiting speed (mechanical) | 1700 rpm |
| Operating temperature | -40 to +120 °C |
| Manufacturer designation | NTN NJ238E |
| 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 | 7.48 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 2.165 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 75 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) | 29 of 36 |
| Bore above smallest NJ200-series size | 175 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ238E | 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 NJ238E model number is decoded
For pure radial duty on a 190 mm shaft NTN supplies NJ238E: two integral ribs on the inner ring and one rib on the outer ring; the open execution is rated 1,700 r/min on grease and 2,000 r/min on oil. Digit by digit, NJ238E reads as NJ (inner ring two ribs + one outer rib), ISO 15 series, and bore 190 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. The separable ring comes off without removing the roller assembly from the other ring, which eases inspection and lets the non-locating arrangement accommodate thermal shaft growth. The 4.1 kN-per-mm-bore figure (770 kN over 190 mm) lets a NJ238E interchange candidate be screened quickly against the same-envelope ball or roller alternatives. 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 NJ238E.
Typical equipment & failure modes
Common applications
- mining SAG/ball-mill drive shafts
- offshore drawworks and winch drums
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- brinelling from static overload or impact during handling
Selection pitfalls — read before you substitute
- At 190 mm bore, oil-lubricated arrangements toward 2,000 r/min need positive flow and drain design; the NJ238E ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Do not replace NJ238E with a deep-groove ball bearing on rating alone: line contact gives 770 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- Grease limiting speed 1,700 r/min and oil 2,000 r/min are different limits for NJ238E: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 770/955 kN pair here belongs to NJ238E as printed, not to the bare size.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 770/955 kN pair here belongs to NJ238E as printed, not to the bare size.
- The 770/955 kN ratings, 86.5 kN Pu are NTN Ball and Roller Bearings CAT.No.2203E values for NJ238E (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 NJ238E?
NJ238E is an NTN NJ single-row cylindrical roller bearing to ISO 15: 190 mm bore, 340 mm OD and 55 mm width (7.48 × 13.386 × 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 770 kN, C0 955 kN, Pu 86.5 kN, grease limiting speed 1,700 r/min, oil 2,000 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. NJ238E 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. NJ238E is supplied in the standard open execution shown in the table.
Can NJ238E 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 NJ238E?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 230 mm. The nominal bore/OD remain 190/340 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,700 r/min grease / 2,000 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.