32907XU bearing: complete specifications & equivalents
The 32907XU is a ISO 355 radial bearing sized 35 x 55 x 14 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 35 mm |
| Outer diameter D | 55 mm |
| Width B | 14 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 30.5 kN |
| Basic static load rating C0 | 37.5 kN |
| Fatigue load limit Pu | 4.6 kN |
| Limiting speed (mechanical) | 6800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 121 g |
| Manufacturer designation | NTN 32907XU |
| 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 | 1.378 in |
|---|---|
| Outer diameter D | 2.165 in |
| Width B | 0.551 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 10 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) | 1 of 37 |
| Bore above smallest 32900-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32907XU | 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 32907XU model number is decoded
For a 35 mm shaft with a thrust component, NTN lists 32907XU, a metric 4T tapered roller bearing of 30.5 kN C and 37.5 kN C0 inside the 55 mm OD, 14 mm-wide assembled set. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 32907XU resolves to 35 mm bore; the NTN factory mark 4T is stamped on cone and cup but is a brand mark, not a size code, so the catalogue sku is printed without it. The 10.0 mm radial section carries the roller complement across the 35–55 mm envelope; section and contact angle differ between NTN metric families even at the same bore, so 302/322/323 are not drop-in swaps. Grease relubrication at 6,800 r/min limiting speed targets the rib contact; if the drive needs 9,000 r/min it must be arranged for oil lubrication with a defined flow to the large roller ends. With a rotating shaft a k5/m5 shaft seat and a press-fit cup are typical catalogue practice for 32907XU; reverse the logic if the cup rotates, and re-verify against load direction and magnitude.
Typical equipment & failure modes
Common applications
- machine-tool gearbox and headstock shafts
- axle final-drive and differential positions
- construction-equipment wheel and pivot hubs
- truck and bus wheel hubs in paired arrangements
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- cage damage from a mounting blow delivered through the roller complement instead of the ring face
- edge loading when shaft deflection exceeds the few arc-minutes of misalignment the adjusted pair allows
Selection pitfalls — read before you substitute
- Hub and pinion bearings of this 35 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 32907XU.
- The thin 14 mm section of 32907XU is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 35 mm bore smears the roller ends against the rib.
- Do not confuse T (14 mm assembled width of cone + cup) with the cone width when drawing spacers; an abutment sized to T instead of the ring width leaves the cup unseated.
- Grease packs must leave free volume in the 14 mm-wide set; over-greasing a paired bearing churning at the 9,000 r/min oil-band speed raises temperature and destroys the preload setting.
- The U/UTG/X/C/CA/D suffix variants of a base number share the bore but not the article: ordering 32907XU by size alone can deliver the wrong contact-angle execution for a pinion position.
- The 30.5/37.5 kN ratings and 4.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32907XU (ISO 355 2BD); 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 32907XU?
32907XU is a metric 4T tapered roller bearing to ISO 355: 35 mm bore, 55 mm outside diameter and 14 mm assembled width T (1.378 × 2.165 × 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 30.5 kN, C0 37.5 kN, Pu 4.6 kN, grease limiting speed 6,800 r/min, oil speed 9,000 r/min, mass about 121 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32907XU?
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 (32907XU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32907XU designation encode the 35 mm bore and what is 2BD?
last two digits 07 are the ISO bore code, ×5 = 35 mm (codes 00–03 use the 10/12/15/17 exception table). The 55 mm OD and 14 mm assembled T follow the ISO 355 dimension-series plan. 2BD 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 32907XU list two speeds, 6,800 and 9,000 r/min?
The lower figure, 6,800 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32907XU at 9,000 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32907XU mean?
Suffix reading on 32907XU: 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.