32915XU bearing: complete specifications & equivalents
The 32915XU is a ISO 355 radial bearing sized 75 x 105 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 75 mm |
| Outer diameter D | 105 mm |
| Width B | 20 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 77 kN |
| Basic static load rating C0 | 114 kN |
| Fatigue load limit Pu | 13.9 kN |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 508 g |
| Manufacturer designation | NTN 32915XU |
| 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 | 2.953 in |
|---|---|
| Outer diameter D | 4.134 in |
| Width B | 0.787 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 15 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) | 9 of 37 |
| Bore above smallest 32900-series size | 40 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32915XU | 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 32915XU model number is decoded
The NTN 2203E table prints 32915XU in the extra-light thin-section 32900 family: 75 mm bore, 105 mm cup OD, 20 mm T, with a grease limiting speed of 3,200 r/min and an oil-lubricated ceiling of 4,300 r/min. The last two digits 15 are the ISO bore code, ×5 = 75 mm (codes 00–03 use the 10/12/15/17 exception table) under the ISO 355 numbering; the 20 mm value printed here is T, the width of the fully assembled cone-plus-cup set, not the inner-ring width alone. A tapered roller bearing reacts combined radial and one-direction axial load; NTN mounts 32915XU cone and cup separately and adjusts end play or preload against a second bearing, so the arrangement locates the shaft in both directions. The fatigue load limit Pu printed for 32915XU is 13.9 kN; in the adjusted-life equation that is the equivalent-load floor below which high reliability is expected even under contamination. Fillet radii must clear the ring chamfers of the 105 mm cup and 75 mm cone; use undercut shoulders so the rings seat fully rather than bridging on a shaft radius.
Typical equipment & failure modes
Common applications
- heavy industrial gearboxes and crane travel drives
- rolling-mill auxiliary and pinion-stand shafts
- large conveyor and bucket-elevator pulleys
- mineral-processing feeder and crusher auxiliaries
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- brinell marks on cone and cup raceways from impact during handling or hammering during fitting
Selection pitfalls — read before you substitute
- Mount the 75 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 508 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The thin 20 mm section of 32915XU is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 75 mm bore smears the roller ends against the rib.
- Replacing one half of an adjusted pair without resetting end play negates the 20 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- ISO 355 makes the 75×105 mm envelope interchangeable but not the ratings: NTN prints 77/114 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- Do not confuse T (20 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.
- The 77/114 kN ratings and 13.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32915XU (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 32915XU?
32915XU is a metric 4T tapered roller bearing to ISO 355: 75 mm bore, 105 mm outside diameter and 20 mm assembled width T (2.953 × 4.134 × 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 77 kN, C0 114 kN, Pu 13.9 kN, grease limiting speed 3,200 r/min, oil speed 4,300 r/min, mass about 508 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32915XU?
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 (32915XU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32915XU designation encode the 75 mm bore and what is 2BC?
last two digits 15 are the ISO bore code, ×5 = 75 mm (codes 00–03 use the 10/12/15/17 exception table). The 105 mm OD and 20 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 32915XU list two speeds, 3,200 and 4,300 r/min?
The lower figure, 3,200 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32915XU at 4,300 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32915XU mean?
Suffix reading on 32915XU: 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.