32938XU bearing: complete specifications & equivalents
The 32938XU is a ISO 355 radial bearing sized 190 x 260 x 45 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 | 260 mm |
| Width B | 45 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 390 kN |
| Basic static load rating C0 | 710 kN |
| Fatigue load limit Pu | 68 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6820 g |
| Manufacturer designation | NTN 32938XU |
| Standard | ISO 355 |
| 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 & 32900-series range
| Bore d | 7.48 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 1.772 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in 32900-series | 35 mm |
| Largest outer diameter in 32900-series | 600 mm |
| Width range across 32900-series | 14–100 mm |
| Bore position in 32900-series (smallest first) | 24 of 37 |
| Bore above smallest 32900-series size | 155 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32938XU | 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 32938XU model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the NTN order number 32938XU denotes the extra-light thin-section 32900 family of metric tapered roller bearings, 190 mm bore, 260 mm outside diameter and 45 mm assembled width T (7.48 × 10.236 × 1.772 in) to the ISO 355 boundary plan. NTN also quotes this bearing with its ISO 355 dimension-series abbreviation, 4DC, which is the maker-neutral cross-reference for the 190×260 mm envelope; 4T is NTN's own tapered-roller brand mark on the parts. NTN grades 4T metric bearings as open bearings without integral seals; at 190 mm bore the application supplies the seals and the grease fill or oil supply to the 4DC ISO 355 assembly. The 2.1 kN-per-mm-bore capacity figure for 32938XU summarises the 390 kN rating over 190 mm bore; use it to sanity-check an interchange candidate before swapping brands. Open 4T bearings need application seals; without them the grease at the cone rib of 32938XU washes out and the rib/roller-end contact smears on the first wet or dusty shift.
Typical equipment & failure modes
Common applications
- rolling-mill roll-neck and gearbox positions
- large crusher and SAG/AG-mill drive shafts
- wind-turbine gearbox and main-shaft arrangements
- offshore crane and drawworks drums
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- rolling-contact fatigue after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- At 190 mm bore the 32938XU set is adjusted with hydraulic nuts on large mill and wind positions; follow the drive-up angle/end-play procedure, because manual torque methods cannot control preload at the 390 kN C level.
- The thin 45 mm section of 32938XU is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 190 mm bore smears the roller ends against the rib.
- The 35.0 mm section leaves little room for an oversized shaft fillet; check the mounting-chamfer table for 32938XU or the ring will bottom out on the radius instead of the shoulder face.
- ISO 355 makes the 190×260 mm envelope interchangeable but not the ratings: NTN prints 390/710 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- The 35.0 mm section leaves little room for an oversized shaft fillet; check the mounting-chamfer table for 32938XU or the ring will bottom out on the radius instead of the shoulder face.
- The 390/710 kN ratings and 68 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32938XU (ISO 355 4DC); internal geometry legitimately differs between manufacturers, so re-verify ratings, adjustment and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 32938XU?
32938XU is a metric 4T tapered roller bearing to ISO 355: 190 mm bore, 260 mm outside diameter and 45 mm assembled width T (7.48 × 10.236 × 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 390 kN, C0 710 kN, Pu 68 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 6820 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32938XU?
4T is NTN's tapered roller bearing brand mark, stamped on the cone and cup in the factory. It identifies the NTN 4T programme and is not a dimension, so the catalogue and this page list the bare ISO 355 number (32938XU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32938XU designation encode the 190 mm bore and what is 4DC?
last two digits 38 are the ISO bore code, ×5 = 190 mm (codes 00–03 use the 10/12/15/17 exception table). The 260 mm OD and 45 mm assembled T follow the ISO 355 dimension-series plan. 4DC is the maker-neutral ISO 355 abbreviation for this dimension series (the same code other manufacturers print); 4T is NTN's own brand mark.
Why does 32938XU list two speeds, 1,200 and 1,600 r/min?
The lower figure, 1,200 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32938XU at 1,600 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32938XU mean?
Suffix reading on 32938XU: XU combines the X ISO boundary section with the U uprated internal design; U marks the reinforced/uprated internal design of the bare number, a separate order number with higher load capacity than the basic execution; the suffix is part of the order number and the variants are not interchangeable articles.
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.