NJ2248 bearing: complete specifications & equivalents
The NJ2248 is a ISO 15 radial bearing sized 240 x 440 x 120 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 240 mm |
| Outer diameter D | 440 mm |
| Width B | 120 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1590 kN |
| Basic static load rating C0 | 2320 kN |
| Fatigue load limit Pu | 196 kN |
| Limiting speed (mechanical) | 1300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 78400 g |
| Manufacturer designation | NTN NJ2248 |
| 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 | 9.449 in |
|---|---|
| Outer diameter D | 17.323 in |
| Width B | 4.724 in |
| ISO bore code | 48 |
| Radial section height (D−d)/2 | 100 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) | 30 of 34 |
| Bore above smallest NJ2200-series size | 223 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ2248-MA | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per 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 NJ2248 model number is decoded
The NTN order number NJ2248 denotes a 240×440×120 mm (9.449 × 17.323 × 4.724 in) cylindrical roller bearing in the NJ2200 family, a pressed sheet-steel cage. Numbering ties NJ2248 to its envelope: type code NJ, series NJ2200, 240 mm bore; the 440×120 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. The 120 mm width and 100.0 mm section put the NJ2200 series in the wide (22) section; wide 22/23 variants at the same bore change OD, width and heat generation and are not drop-in swaps. Equivalent-load planning treats NJ2248 as a pure radial bearing: keep P below 1590 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 NJ2248 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
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- false brinelling on standby machines exposed to external vibration
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 240 mm bore, oil-lubricated arrangements toward 1,600 r/min need positive flow and drain design; the 78400 g NJ2248 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Open NJ2248 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 240 mm contact.
- Wide (22/23) and light (10/49) executions at 240 mm bore share bore but not OD/width; check the full NJ2200 series code before substituting, because housing and shoulder geometry will not interchange.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 1590/2320 kN pair here belongs to NJ2248 as printed, not to the bare size.
- Open NJ2248 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 240 mm contact.
- The 1590/2320 kN ratings, 196 kN Pu and 78400 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ2248 (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 NJ2248?
NJ2248 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 240 mm bore, 440 mm OD and 120 mm width (9.449 × 17.323 × 4.724 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1590 kN, C0 2320 kN, Pu 196 kN, grease limiting speed 1,300 r/min, oil 1,600 r/min, mass about 78400 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. NJ2248 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. NJ2248 is supplied in the standard open execution shown in the table.
Can NJ2248 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 NJ2248?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 295 mm, Ew 385 mm. The nominal bore/OD remain 240/440 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,300 r/min grease / 1,600 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.