NJ2238 bearing: complete specifications & equivalents
The NJ2238 is a ISO 15 radial bearing sized 190 x 340 x 92 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 | 92 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 920 kN |
| Basic static load rating C0 | 1290 kN |
| Fatigue load limit Pu | 117 kN |
| Limiting speed (mechanical) | 1700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 33700 g |
| Manufacturer designation | NTN NJ2238 |
| 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 & NJ2200-series range
| Bore d | 7.48 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 3.622 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 75 mm |
| Smallest bore in NJ2200-series | 17 mm |
| Largest outer diameter in NJ2200-series | 580 mm |
| Width range across NJ2200-series | 16–150 mm |
| Bore position in NJ2200-series (smallest first) | 27 of 34 |
| Bore above smallest NJ2200-series size | 173 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ2238-ECML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 190×340×92 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 NJ2238 model number is decoded
NTN lists NJ2238 on the 190×340 mm envelope, 92 mm wide: a line-contact radial bearing with a pressed sheet-steel cage and a grease limiting speed of 1,700 r/min. Digit by digit, NJ2238 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. Minimum radial load matters: an unloaded NJ2238 at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Speed ratio check: limiting 1,700 r/min is .85 of the 2,000 r/min oil value for NJ2238; grease-churn heating closes that gap as fill quantity rises. Housing and shaft fillets must clear the ring chamfers of NJ2238; an oversized radius locks the ring on its face and tilts the 92 mm-wide seat.
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 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
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- 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 33700 g NJ2238 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Wide (22/23) and light (10/49) executions at 190 mm bore share bore but not OD/width; check the full NJ2200 series code before substituting, because housing and shoulder geometry will not interchange.
- If the shaft must be located both ways, do not use NJ2238 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 340 mm race brinells and releases as vibration within hours.
- Do not replace NJ2238 with a deep-groove ball bearing on rating alone: line contact gives 920 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 920/1290 kN ratings, 117 kN Pu and 33700 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ2238 (standard 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 NJ2238?
NJ2238 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 190 mm bore, 340 mm OD and 92 mm width (7.48 × 13.386 × 3.622 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 920 kN, C0 1290 kN, Pu 117 kN, grease limiting speed 1,700 r/min, oil 2,000 r/min, mass about 33700 g. It is open, with a 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. NJ2238 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. NJ2238 is supplied in the standard open execution shown in the table.
Can NJ2238 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 NJ2238?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 231 mm, Ew 299 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.