NJ2324 bearing: complete specifications & equivalents
The NJ2324 is a ISO 15 radial bearing sized 120 x 260 x 86 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 120 mm |
| Outer diameter D | 260 mm |
| Width B | 86 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 785 kN |
| Basic static load rating C0 | 920 kN |
| Fatigue load limit Pu | 92.5 kN |
| Limiting speed (mechanical) | 2400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 21100 g |
| Manufacturer designation | NTN NJ2324 |
| 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 & NJ2300-series range
| Bore d | 4.724 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 3.386 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in NJ2300-series | 20 mm |
| Largest outer diameter in NJ2300-series | 580 mm |
| Width range across NJ2300-series | 21–175 mm |
| Bore position in NJ2300-series (smallest first) | 19 of 31 |
| Bore above smallest NJ2300-series size | 100 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ2324-ECML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 120×260×86 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 NJ2324 model number is decoded
For pure radial duty on a 120 mm shaft NTN supplies NJ2324: two integral ribs on the inner ring and one rib on the outer ring; the open execution is rated 2,400 r/min on grease and 2,800 r/min on oil. On the NTN nameplate NJ states which ring carries the ribs, which determines whether NJ2324 floats or locates; the numeric remainder is the ISO 15 series and 120 mm bore reference, not a fit or clearance instruction. With C 785 kN and C0 920 kN (C0/C ≈ 1.17) the bearing is proportioned for heavy radial load; the NJ design accepts axial load in one direction and provides one-way shaft location. With the inner ring rotating, catalogue practice is a m6/n6 shaft seat and an H7/H6 housing; the outer ring must remain free to creep slightly axially in non-locating NJ arrangements. Heat the inner ring to max 120 °C for the 120 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
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- brinelling from static overload or impact during handling
- false brinelling on standby machines exposed to external vibration
Selection pitfalls — read before you substitute
- At 120 mm bore, oil-lubricated arrangements toward 2,800 r/min need positive flow and drain design; the 21100 g NJ2324 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Wide (22/23) and light (10/49) executions at 120 mm bore share bore but not OD/width; check the full NJ2300 series code before substituting, because housing and shoulder geometry will not interchange.
- The NJ rib arrangement is not interchangeable with another prefix on the same 120 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 260×86 mm envelope matches.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 785/920 kN pair here belongs to NJ2324 as printed, not to the bare size.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NJ2324 skids at 2,400 r/min and fails by smearing long before L10 fatigue.
- The 785/920 kN ratings, 92.5 kN Pu and 21100 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ2324 (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 NJ2324?
NJ2324 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 120 mm bore, 260 mm OD and 86 mm width (4.724 × 10.236 × 3.386 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 785 kN, C0 920 kN, Pu 92.5 kN, grease limiting speed 2,400 r/min, oil 2,800 r/min, mass about 21100 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. NJ2324 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. NJ2324 is supplied in the standard open execution shown in the table.
Can NJ2324 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 NJ2324?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 154 mm, Ew 226 mm. The nominal bore/OD remain 120/260 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,400 r/min grease / 2,800 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.