32908XU bearing: complete specifications & equivalents
The 32908XU is a ISO 355 radial bearing sized 40 x 62 x 15 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 40 mm |
| Outer diameter D | 62 mm |
| Width B | 15 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 36 kN |
| Basic static load rating C0 | 48 kN |
| Fatigue load limit Pu | 5.85 kN |
| Limiting speed (mechanical) | 5900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 161 g |
| Manufacturer designation | NTN 32908XU |
| 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 | 1.575 in |
|---|---|
| Outer diameter D | 2.441 in |
| Width B | 0.591 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 11 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) | 2 of 37 |
| Bore above smallest 32900-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32908XU | 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 32908XU model number is decoded
32908XU is a metric single-row tapered roller bearing in the NTN 4T programme: a pressed-steel cage guides profiled rollers between a separable cone and cup on the 40×62 mm ISO 355 envelope, with 15 mm overall assembled width T. Digit by digit, the bare number identifies the extra-light thin-section 32900 family and a bore code resolving to 40 mm; 62 mm OD and 15 mm assembled T are the matching ISO 355 boundary dimensions shared with other makers of the same dimension series. Suffix reading on 32908XU: 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. The two speed columns differ by a factor of .76 (grease/limiting 5,900 vs oil 7,800 r/min); heat generation at the cone rib decides which lubrication a real 32908XU arrangement can sustain. Mount the 40 mm-bore cone on the shaft first (induction heat, max 120 °C), fit the cup square in its housing, then set preload or end play; never drive the cup home through the rollers of 32908XU.
Typical equipment & failure modes
Common applications
- bevel and helical pinion drives with high thrust component
- pump and compressor drive shafts carrying combined load
- machine-tool gearbox and headstock shafts
- axle final-drive and differential positions
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- 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
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- brinell marks on cone and cup raceways from impact during handling or hammering during fitting
Selection pitfalls — read before you substitute
- Hub and pinion bearings of this 40 mm bore class are commonly adjusted in pairs; verify end play against the axle drawing and re-torque after bedding-in rather than trusting the initial preload on 32908XU.
- The thin 15 mm section of 32908XU is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 40 mm bore smears the roller ends against the rib.
- ISO 355 makes the 40×62 mm envelope interchangeable but not the ratings: NTN prints 36/48 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 40 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- ISO 355 makes the 40×62 mm envelope interchangeable but not the ratings: NTN prints 36/48 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- The 36/48 kN ratings and 5.85 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32908XU (ISO 355 2BC); 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 32908XU?
32908XU is a metric 4T tapered roller bearing to ISO 355: 40 mm bore, 62 mm outside diameter and 15 mm assembled width T (1.575 × 2.441 × 0.591 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 36 kN, C0 48 kN, Pu 5.85 kN, grease limiting speed 5,900 r/min, oil speed 7,800 r/min, mass about 161 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32908XU?
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 (32908XU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32908XU designation encode the 40 mm bore and what is 2BC?
last two digits 08 are the ISO bore code, ×5 = 40 mm (codes 00–03 use the 10/12/15/17 exception table). The 62 mm OD and 15 mm assembled T follow the ISO 355 dimension-series plan. 2BC 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 32908XU list two speeds, 5,900 and 7,800 r/min?
The lower figure, 5,900 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32908XU at 7,800 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32908XU mean?
Suffix reading on 32908XU: 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.