NU2228 bearing: complete specifications & equivalents
The NU2228 is a ISO 15 radial bearing sized 140 x 250 x 68 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 140 mm |
| Outer diameter D | 250 mm |
| Width B | 68 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 495 kN |
| Basic static load rating C0 | 635 kN |
| Fatigue load limit Pu | 63.5 kN |
| Limiting speed (mechanical) | 2400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12600 g |
| Manufacturer designation | NTN NU2228 |
| 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 & NU2200-series range
| Bore d | 5.512 in |
|---|---|
| Outer diameter D | 9.843 in |
| Width B | 2.677 in |
| ISO bore code | 28 |
| Radial section height (D−d)/2 | 55 mm |
| Smallest bore in NU2200-series | 17 mm |
| Largest outer diameter in NU2200-series | 1030 mm |
| Width range across NU2200-series | 16–272 mm |
| Bore position in NU2200-series (smallest first) | 22 of 39 |
| Bore above smallest NU2200-series size | 123 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU2228-ECML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 140×250×68 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 NU2228 model number is decoded
NTN lists NU2228 on the 140×250 mm envelope, 68 mm wide: a line-contact radial bearing with a pressed sheet-steel cage and a grease limiting speed of 2,400 r/min. Numbering ties NU2228 to its envelope: type code NU, series NU2200, 140 mm bore; the 250×68 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. The 55.0 mm radial section ((250−140)/2) frames the roller complement; capacity per millimetre of bore is about 3.5 kN/mm before application factors. The 3.5 kN-per-mm-bore figure (495 kN over 140 mm) lets a NU2228 interchange candidate be screened quickly against the same-envelope ball or roller alternatives. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NU2228 non-locating position preloads the bearing when the shaft grows.
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
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- At 140 mm bore, oil-lubricated arrangements toward 2,800 r/min need positive flow and drain design; the 12600 g NU2228 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Open NU2228 units need application-supplied sealing and a defined lubricant schedule; film thickness is the first failure mode for line contact when viscosity drops at the 140 mm contact.
- The 68 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 140 mm inner ring.
- Grease limiting speed 2,400 r/min and oil 2,800 r/min are different limits for NU2228: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 55.0 mm section at 140 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 68 mm-wide cavity.
- The 495/635 kN ratings, 63.5 kN Pu and 12600 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU2228 (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 NU2228?
NU2228 is an NTN NU single-row cylindrical roller bearing to ISO 15: 140 mm bore, 250 mm OD and 68 mm width (5.512 × 9.843 × 2.677 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 495 kN, C0 635 kN, Pu 63.5 kN, grease limiting speed 2,400 r/min, oil 2,800 r/min, mass about 12600 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. NU2228 is two integral ribs on the outer ring and a ribless, separable inner ring — a non-locating bearing that lets the shaft float axially.
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. NU2228 is supplied in the standard open execution shown in the table.
Can NU2228 take axial load and locate a shaft?
the NU design carries no axial load and floats axially on both sides. 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 NU2228?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 169 mm, Ew 221 mm. The nominal bore/OD remain 140/250 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,400 r/min grease / 2,800 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.