NU2238 bearing: complete specifications & equivalents
The NU2238 is a ISO 15 radial bearing sized 190 x 340 x 92 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 190 mm |
| Outer diameter D | 340 mm |
| Width B | 92 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 920 kN |
| Basic static load rating C0 | 1290 kN |
| Fatigue load limit Pu | 117 kN |
| Limiting speed (mechanical) | 1700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 33700 g |
| Manufacturer designation | NTN NU2238 |
| 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 | 7.48 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 3.622 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 75 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) | 27 of 39 |
| Bore above smallest NU2200-series size | 173 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU2238-ECML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 190×340×92 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 NU2238 model number is decoded
The NTN order number NU2238 denotes a 190×340×92 mm (7.48 × 13.386 × 3.622 in) cylindrical roller bearing in the NU2200 family, a pressed sheet-steel cage. The leading NU defines the rib arrangement (outer ring ribbed, inner ring ribless); the dimension-series digits and the two-digit bore code resolve to 190 mm, with 340 mm OD and 92 mm width from the ISO 15 general plan. The separable ring comes off without removing the roller assembly from the other ring, which eases inspection and lets the non-locating arrangement accommodate thermal shaft growth — the NU design floats on both sides. With the inner ring rotating, catalogue practice is a m6/n6 shaft seat and an H7/H6 housing; the outer ring must remain free to creep slightly axially in non-locating NU arrangements. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of NU2238.
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
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- fretting corrosion on a loose rotating shaft seat
- hard-particle indentation of raceways in unfiltered oil or open arrangements
Selection pitfalls — read before you substitute
- At 190 mm bore, oil-lubricated arrangements toward 2,000 r/min need positive flow and drain design; the 33700 g NU2238 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Do not replace NU2238 with a deep-groove ball bearing on rating alone: line contact gives 920 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- Open NU2238 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 190 mm contact.
- Open NU2238 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 190 mm contact.
- The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 920/1290 kN pair here belongs to NU2238 as printed, not to the bare size.
- The 920/1290 kN ratings, 117 kN Pu and 33700 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU2238 (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 NU2238?
NU2238 is an NTN NU single-row cylindrical roller bearing to ISO 15: 190 mm bore, 340 mm OD and 92 mm width (7.48 × 13.386 × 3.622 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 920 kN, C0 1290 kN, Pu 117 kN, grease limiting speed 1,700 r/min, oil 2,000 r/min, mass about 33700 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. NU2238 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. NU2238 is supplied in the standard open execution shown in the table.
Can NU2238 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 NU2238?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 231 mm, Ew 299 mm. The nominal bore/OD remain 190/340 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,700 r/min grease / 2,000 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.