NJ230 bearing: complete specifications & equivalents
The NJ230 is a ISO 15 radial bearing sized 150 x 270 x 45 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 150 mm |
| Outer diameter D | 270 mm |
| Width B | 45 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 380 kN |
| Basic static load rating C0 | 435 kN |
| Fatigue load limit Pu | 42.5 kN |
| Limiting speed (mechanical) | 2500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 9720 g |
| Manufacturer designation | NTN NJ230 |
| 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 | 5.906 in |
|---|---|
| Outer diameter D | 10.63 in |
| Width B | 1.772 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 60 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) | 25 of 36 |
| Bore above smallest NJ200-series size | 135 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ230-ECM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 150×270×45 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 NJ230 model number is decoded
For pure radial duty on a 150 mm shaft NTN supplies NJ230: two integral ribs on the inner ring and one rib on the outer ring; the open execution is rated 2,500 r/min on grease and 2,900 r/min on oil. Numbering ties NJ230 to its envelope: type code NJ, series NJ200, 150 mm bore; the 270×45 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. NTN prints the raceway diameters for this size — Fw 182 mm and Ew 238 mm — the envelope inside the 150/270 mm bore/OD where the rollers actually run. Equivalent-load planning treats NJ230 as a pure radial bearing: keep P below 380 kN at the required L10, and let a paired angular-contact or thrust part carry any sustained axial component. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NJ230 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- offshore drawworks and winch drums
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- hard-particle indentation of raceways in unfiltered oil or open arrangements
Selection pitfalls — read before you substitute
- At 150 mm bore, oil-lubricated arrangements toward 2,900 r/min need positive flow and drain design; the 9720 g NJ230 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 270 mm race brinells and releases as vibration within hours.
- Open NJ230 units need application-supplied sealing and a defined lubricant schedule; film thickness is the first failure mode for line contact when viscosity drops at the 150 mm contact.
- The NJ rib arrangement is not interchangeable with another prefix on the same 150 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 270×45 mm envelope matches.
- The NJ rib arrangement is not interchangeable with another prefix on the same 150 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 270×45 mm envelope matches.
- The 380/435 kN ratings, 42.5 kN Pu and 9720 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ230 (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 NJ230?
NJ230 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 150 mm bore, 270 mm OD and 45 mm width (5.906 × 10.63 × 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 380 kN, C0 435 kN, Pu 42.5 kN, grease limiting speed 2,500 r/min, oil 2,900 r/min, mass about 9720 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. NJ230 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. NJ230 is supplied in the standard open execution shown in the table.
Can NJ230 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 NJ230?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 182 mm, Ew 238 mm. The nominal bore/OD remain 150/270 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,500 r/min grease / 2,900 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.