NJ1056 bearing: complete specifications & equivalents
The NJ1056 is a ISO 15 radial bearing sized 280 x 420 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 | 280 mm |
| Outer diameter D | 420 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 730 kN |
| Basic static load rating C0 | 1050 kN |
| Fatigue load limit Pu | 88 kN |
| Limiting speed (mechanical) | 1500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 30400 g |
| Manufacturer designation | NTN NJ1056 |
| 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 | 11.024 in |
|---|---|
| Outer diameter D | 16.535 in |
| Width B | 2.559 in |
| ISO bore code | 56 |
| Radial section height (D−d)/2 | 70 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) | 31 of 42 |
| Bore above smallest NJ1000-series size | 255 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ1056 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the 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 NJ1056 model number is decoded
For pure radial duty on a 280 mm shaft NTN supplies NJ1056: two integral ribs on the inner ring and one rib on the outer ring; the open execution is rated 1,500 r/min on grease and 1,800 r/min on oil. On the NTN nameplate NJ states which ring carries the ribs, which determines whether NJ1056 floats or locates; the numeric remainder is the ISO 15 series and 280 mm bore reference, not a fit or clearance instruction. NTN ships these bearings open with normal (CN) radial clearance and P0 tolerance as standard; precision classes and C3/C4 clearance are separate order suffixes, not part of NJ1056. Selection arithmetic: Pu 88 kN is the fatigue load limit feeding the adjusted-life equation, and the C0/C ratio of 1.44 (1050/730 kN) shows the high-static-capacity proportioning of this 280 mm bore. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NJ1056 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 distortion after a mounting blow carried through the roller set
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- hard-particle indentation of raceways in unfiltered oil or open arrangements
Selection pitfalls — read before you substitute
- At 280 mm bore, oil-lubricated arrangements toward 1,800 r/min need positive flow and drain design; the 30400 g NJ1056 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- If the shaft must be located both ways, do not use NJ1056 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 730/1050 kN pair here belongs to NJ1056 as printed, not to the bare size.
- The 70.0 mm section at 280 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 65 mm-wide cavity.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 420 mm race brinells and releases as vibration within hours.
- The 730/1050 kN ratings, 88 kN Pu and 30400 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ1056 (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 NJ1056?
NJ1056 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 280 mm bore, 420 mm OD and 65 mm width (11.024 × 16.535 × 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 730 kN, C0 1050 kN, Pu 88 kN, grease limiting speed 1,500 r/min, oil 1,800 r/min, mass about 30400 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. NJ1056 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. NJ1056 is supplied in the standard open execution shown in the table.
Can NJ1056 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 NJ1056?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 316 mm, Ew 384 mm. The nominal bore/OD remain 280/420 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,500 r/min grease / 1,800 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.