N2256 bearing: complete specifications & equivalents
The N2256 is a ISO 15 radial bearing sized 280 x 500 x 130 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 | 500 mm |
| Width B | 130 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 2050 kN |
| Basic static load rating C0 | 3100 kN |
| Fatigue load limit Pu | 252 kN |
| Limiting speed (mechanical) | 1100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 107000 g |
| Manufacturer designation | NTN N2256 |
| 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 & N2200-series range
| Bore d | 11.024 in |
|---|---|
| Outer diameter D | 19.685 in |
| Width B | 5.118 in |
| ISO bore code | 56 |
| Radial section height (D−d)/2 | 110 mm |
| Smallest bore in N2200-series | 20 mm |
| Largest outer diameter in N2200-series | 580 mm |
| Width range across N2200-series | 18–150 mm |
| Bore position in N2200-series (smallest first) | 31 of 33 |
| Bore above smallest N2200-series size | 260 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N2256 | 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 N2256 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, N2256 appears as a 280 mm bore single-row cylindrical roller bearing (2050 kN C / 3100 kN C0) with a pressed sheet-steel cage, listed to the ISO 15 boundary plan. The leading N defines the rib arrangement (inner ring ribbed, outer ring ribless); the dimension-series digits and the two-digit bore code resolve to 280 mm, with 500 mm OD and 130 mm width from the ISO 15 general plan. With C 2050 kN and C0 3100 kN (C0/C ≈ 1.51) the bearing is proportioned for heavy radial load; the N design is non-locating like NU but floats with the separable outer ring in the housing. Equivalent-load planning treats N2256 as a pure radial bearing: keep P below 2050 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 N2256 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
- 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
- brinelling from static overload or impact during handling
- 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 1,300 r/min need positive flow and drain design; the 107000 g N2256 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The 130 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 280 mm inner ring.
- If the shaft must be located both ways, do not use N2256 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 130 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 280 mm inner ring.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded N2256 skids at 1,100 r/min and fails by smearing long before L10 fatigue.
- The 2050/3100 kN ratings, 252 kN Pu and 107000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N2256 (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 N2256?
N2256 is an NTN N single-row cylindrical roller bearing to ISO 15: 280 mm bore, 500 mm OD and 130 mm width (11.024 × 19.685 × 5.118 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 2050 kN, C0 3100 kN, Pu 252 kN, grease limiting speed 1,100 r/min, oil 1,300 r/min, mass about 107000 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. N2256 is two integral ribs on the inner ring and a ribless separable outer ring — equivalent float behaviour with the separable ring on the housing side.
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. N2256 is supplied in the standard open execution shown in the table.
Can N2256 take axial load and locate a shaft?
the N design is non-locating like NU but floats with the separable outer ring in the housing. Provide axial location with an adjacent locating bearing (angular-contact, deep-groove or a paired NJ/NUP set).
What do Fw and Ew mean for N2256?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 340 mm, Ew 440 mm. The nominal bore/OD remain 280/500 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,100 r/min grease / 1,300 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.