NU2338 bearing: complete specifications & equivalents
The NU2338 is a ISO 15 radial bearing sized 190 x 400 x 132 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 | 400 mm |
| Width B | 132 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1680 kN |
| Basic static load rating C0 | 2220 kN |
| Fatigue load limit Pu | 196 kN |
| Limiting speed (mechanical) | 1400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 78900 g |
| Manufacturer designation | NTN NU2338 |
| 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 & NU2300-series range
| Bore d | 7.48 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 5.197 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 105 mm |
| Smallest bore in NU2300-series | 20 mm |
| Largest outer diameter in NU2300-series | 750 mm |
| Width range across NU2300-series | 21–224 mm |
| Bore position in NU2300-series (smallest first) | 26 of 35 |
| Bore above smallest NU2300-series size | 170 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU2338-ECML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 190×400×132 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 NU2338 model number is decoded
NU2338 is an NTN NU cylindrical roller bearing: two integral ribs on the outer ring and a ribless, separable inner ring — a non-locating bearing that lets the shaft float axially, inside the 190×400×132 mm ISO 15 envelope. Reading the code: NU for the non-locating separable-inner-ring type, then the ISO 15 diameter/width series and the bore code — ×5 = 190 mm (00–03 use the 10/12/15/17 exception table). Minimum radial load matters: an unloaded NU2338 at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Rating life at 1680 kN C assumes clean oil and adequate film; the 196 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. 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 NU2338.
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
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- roller-end and raceway scoring from inadequate oil flow under heavy radial load
- false brinelling on standby machines exposed to external vibration
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 190 mm bore, oil-lubricated arrangements toward 1,700 r/min need positive flow and drain design; the 78900 g NU2338 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- The NU rib arrangement is not interchangeable with another prefix on the same 190 mm seat: outer ring ribbed, inner ring ribless. Swapping NU for NJ changes axial location behaviour even though the 400×132 mm envelope matches.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NU2338 skids at 1,400 r/min and fails by smearing long before L10 fatigue.
- Grease limiting speed 1,400 r/min and oil 1,700 r/min are different limits for NU2338: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Do not replace NU2338 with a deep-groove ball bearing on rating alone: line contact gives 1680 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- The 1680/2220 kN ratings, 196 kN Pu and 78900 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU2338 (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 NU2338?
NU2338 is an NTN NU single-row cylindrical roller bearing to ISO 15: 190 mm bore, 400 mm OD and 132 mm width (7.48 × 15.748 × 5.197 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1680 kN, C0 2220 kN, Pu 196 kN, grease limiting speed 1,400 r/min, oil 1,700 r/min, mass about 78900 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. NU2338 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. NU2338 is supplied in the standard open execution shown in the table.
Can NU2338 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 NU2338?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 245 mm, Ew 345 mm. The nominal bore/OD remain 190/400 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,400 r/min grease / 1,700 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.