NJ244 bearing: complete specifications & equivalents
The NJ244 is a ISO 15 radial bearing sized 220 x 400 x 65 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 220 mm |
| Outer diameter D | 400 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 845 kN |
| Basic static load rating C0 | 1080 kN |
| Fatigue load limit Pu | 94 kN |
| Limiting speed (mechanical) | 1600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 37000 g |
| Manufacturer designation | NTN NJ244 |
| 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 | 8.661 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 2.559 in |
| ISO bore code | 44 |
| Radial section height (D−d)/2 | 90 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) | 31 of 36 |
| Bore above smallest NJ200-series size | 205 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ244-ECML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 220×400×65 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 NJ244 model number is decoded
For pure radial duty on a 220 mm shaft NTN supplies NJ244: two integral ribs on the inner ring and one rib on the outer ring; the open execution is rated 1,600 r/min on grease and 1,900 r/min on oil. Reading the code: NJ for the one-direction-locating type, then the ISO 15 diameter/width series and the bore code — ×5 = 220 mm (00–03 use the 10/12/15/17 exception table). NTN prints two speed ceilings: 1,600 r/min grease and 1,900 r/min oil — the pressed-steel cage and lubricant film set the real limit at the 220 mm bore. Rating life at 845 kN C assumes clean oil and adequate film; the 94 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. Keep the open bearing wrapped until fitting: the line-contact raceways of the 220 mm bore indent under a single hard particle, and the steel cage provides no sealing of its own.
Typical equipment & failure modes
Common applications
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
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
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- fretting corrosion on a loose rotating shaft seat
- brinelling from static overload or impact during handling
Selection pitfalls — read before you substitute
- At 220 mm bore, oil-lubricated arrangements toward 1,900 r/min need positive flow and drain design; the 37000 g NJ244 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NJ244 skids at 1,600 r/min and fails by smearing long before L10 fatigue.
- The 65 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 220 mm inner ring.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 400 mm race brinells and releases as vibration within hours.
- If the shaft must be located both ways, do not use NJ244 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 845/1080 kN ratings, 94 kN Pu and 37000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ244 (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 NJ244?
NJ244 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 220 mm bore, 400 mm OD and 65 mm width (8.661 × 15.748 × 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 845 kN, C0 1080 kN, Pu 94 kN, grease limiting speed 1,600 r/min, oil 1,900 r/min, mass about 37000 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. NJ244 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. NJ244 is supplied in the standard open execution shown in the table.
Can NJ244 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 NJ244?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 270 mm, Ew 350 mm. The nominal bore/OD remain 220/400 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,600 r/min grease / 1,900 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.