NJ228 bearing: complete specifications & equivalents
The NJ228 is a ISO 15 radial bearing sized 140 x 250 x 42 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 140 mm |
| Outer diameter D | 250 mm |
| Width B | 42 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 345 kN |
| Basic static load rating C0 | 400 kN |
| Fatigue load limit Pu | 39.5 kN |
| Limiting speed (mechanical) | 2700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7720 g |
| Manufacturer designation | NTN NJ228 |
| 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 | 5.512 in |
|---|---|
| Outer diameter D | 9.843 in |
| Width B | 1.654 in |
| ISO bore code | 28 |
| Radial section height (D−d)/2 | 55 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) | 24 of 36 |
| Bore above smallest NJ200-series size | 125 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ228-ECJ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 140×250×42 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 NJ228 model number is decoded
NTN lists NJ228 on the 140×250 mm envelope, 42 mm wide: a line-contact radial bearing with a pressed sheet-steel cage and a grease limiting speed of 2,700 r/min. Reading the code: NJ for the one-direction-locating type, then the ISO 15 diameter/width series and the bore code — ×5 = 140 mm (00–03 use the 10/12/15/17 exception table). NTN prints two speed ceilings: 2,700 r/min grease and 3,100 r/min oil — the pressed-steel cage and lubricant film set the real limit at the 140 mm bore. The 140 mm (5.512 in) bore and 250 mm (9.843 in) OD are ISO 15 boundary values; fillet and shoulder dimensions must still come from the NTN mounting table for the 42 mm-wide ring. Heat the inner ring to max 120 °C for the 140 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.
Typical equipment & failure modes
Common applications
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
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
- electrical pitting on VFD-driven motor shafts without grounding protection
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 140 mm bore, oil-lubricated arrangements toward 3,100 r/min need positive flow and drain design; the 7720 g NJ228 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The NJ rib arrangement is not interchangeable with another prefix on the same 140 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 250×42 mm envelope matches.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 250 mm race brinells and releases as vibration within hours.
- If the shaft must be located both ways, do not use NJ228 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- If the shaft must be located both ways, do not use NJ228 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 345/400 kN ratings, 39.5 kN Pu and 7720 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ228 (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 NJ228?
NJ228 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 140 mm bore, 250 mm OD and 42 mm width (5.512 × 9.843 × 1.654 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 345 kN, C0 400 kN, Pu 39.5 kN, grease limiting speed 2,700 r/min, oil 3,100 r/min, mass about 7720 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. NJ228 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. NJ228 is supplied in the standard open execution shown in the table.
Can NJ228 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 NJ228?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 169 mm, Ew 221 mm. The nominal bore/OD remain 140/250 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,700 r/min grease / 3,100 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.