NJ326 bearing: complete specifications & equivalents
The NJ326 is a ISO 15 radial bearing sized 130 x 280 x 58 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 130 mm |
| Outer diameter D | 280 mm |
| Width B | 58 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 620 kN |
| Basic static load rating C0 | 665 kN |
| Fatigue load limit Pu | 65.5 kN |
| Limiting speed (mechanical) | 2500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 17000 g |
| Manufacturer designation | NTN NJ326 |
| 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 & NJ300-series range
| Bore d | 5.118 in |
|---|---|
| Outer diameter D | 11.024 in |
| Width B | 2.283 in |
| ISO bore code | 26 |
| Radial section height (D−d)/2 | 75 mm |
| Smallest bore in NJ300-series | 17 mm |
| Largest outer diameter in NJ300-series | 580 mm |
| Width range across NJ300-series | 14–108 mm |
| Bore position in NJ300-series (smallest first) | 22 of 33 |
| Bore above smallest NJ300-series size | 113 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ326-ECJ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 130×280×58 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 NJ326 model number is decoded
NTN lists NJ326 on the 130×280 mm envelope, 58 mm wide: a line-contact radial bearing with a pressed sheet-steel cage and a grease limiting speed of 2,500 r/min. Digit by digit, NJ326 reads as NJ (inner ring two ribs + one outer rib), ISO 15 series, and bore 130 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. At 2,900 r/min with oil versus 2,500 r/min with grease (a 400 r/min band), lubrication choice for NJ326 is a thermal decision, not just a sealing one. Equivalent-load planning treats NJ326 as a pure radial bearing: keep P below 620 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 NJ326 non-locating position preloads the bearing when the shaft grows.
Typical equipment & failure modes
Common applications
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
- mining SAG/ball-mill drive shafts
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
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 130 mm bore, oil-lubricated arrangements toward 2,900 r/min need positive flow and drain design; the 17000 g NJ326 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The 58 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 130 mm inner ring.
- Grease limiting speed 2,500 r/min and oil 2,900 r/min are different limits for NJ326: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NJ326 skids at 2,500 r/min and fails by smearing long before L10 fatigue.
- Grease limiting speed 2,500 r/min and oil 2,900 r/min are different limits for NJ326: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 620/665 kN ratings, 65.5 kN Pu and 17000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ326 (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 NJ326?
NJ326 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 130 mm bore, 280 mm OD and 58 mm width (5.118 × 11.024 × 2.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 620 kN, C0 665 kN, Pu 65.5 kN, grease limiting speed 2,500 r/min, oil 2,900 r/min, mass about 17000 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. NJ326 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. NJ326 is supplied in the standard open execution shown in the table.
Can NJ326 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 NJ326?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 167 mm, Ew 243 mm. The nominal bore/OD remain 130/280 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.