NJ1084 bearing: complete specifications & equivalents
The NJ1084 is a ISO 15 radial bearing sized 420 x 620 x 90 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 420 mm |
| Outer diameter D | 620 mm |
| Width B | 90 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1500 kN |
| Basic static load rating C0 | 2290 kN |
| Fatigue load limit Pu | 170 kN |
| Limiting speed (mechanical) | 950 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 89600 g |
| Manufacturer designation | NTN NJ1084 |
| 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 & NJ1000-series range
| Bore d | 16.535 in |
|---|---|
| Outer diameter D | 24.409 in |
| Width B | 3.543 in |
| ISO bore code | 84 |
| Radial section height (D−d)/2 | 100 mm |
| Smallest bore in NJ1000-series | 25 mm |
| Largest outer diameter in NJ1000-series | 720 mm |
| Width range across NJ1000-series | 12–100 mm |
| Bore position in NJ1000-series (smallest first) | 38 of 42 |
| Bore above smallest NJ1000-series size | 395 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ1084 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 NJ1084 model number is decoded
For pure radial duty on a 420 mm shaft NTN supplies NJ1084: two integral ribs on the inner ring and one rib on the outer ring; the open execution is rated 950 r/min on grease and 1,100 r/min on oil. Digit by digit, NJ1084 reads as NJ (inner ring two ribs + one outer rib), ISO 15 series, and bore 420 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. NTN prints two speed ceilings: 950 r/min grease and 1,100 r/min oil — the pressed-steel cage and lubricant film set the real limit at the 420 mm bore. Rating life at 1500 kN C assumes clean oil and adequate film; the 170 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. Heat the inner ring to max 120 °C for the 420 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
- mining SAG/ball-mill drive shafts
- offshore drawworks and winch drums
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- 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
- brinelling from static overload or impact during handling
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 420 mm bore, oil-lubricated arrangements toward 1,100 r/min need positive flow and drain design; the 89600 g NJ1084 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Wide (22/23) and light (10/49) executions at 420 mm bore share bore but not OD/width; check the full NJ1000 series code before substituting, because housing and shoulder geometry will not interchange.
- Grease limiting speed 950 r/min and oil 1,100 r/min are different limits for NJ1084: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Grease limiting speed 950 r/min and oil 1,100 r/min are different limits for NJ1084: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- If the shaft must be located both ways, do not use NJ1084 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 1500/2290 kN ratings, 170 kN Pu and 89600 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ1084 (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 NJ1084?
NJ1084 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 420 mm bore, 620 mm OD and 90 mm width (16.535 × 24.409 × 3.543 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1500 kN, C0 2290 kN, Pu 170 kN, grease limiting speed 950 r/min, oil 1,100 r/min, mass about 89600 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. NJ1084 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. NJ1084 is supplied in the standard open execution shown in the table.
Can NJ1084 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 NJ1084?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 470 mm, Ew 570 mm. The nominal bore/OD remain 420/620 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 950 r/min grease / 1,100 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.