32956XUUTG bearing: complete specifications & equivalents
The 32956XUUTG is a ISO 355 radial bearing sized 280 x 380 x 63.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 280 mm |
| Outer diameter D | 380 mm |
| Width B | 63.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 930 kN |
| Basic static load rating C0 | 1520 kN |
| Fatigue load limit Pu | 129 kN |
| Limiting speed (mechanical) | 790 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 19900 g |
| Manufacturer designation | NTN 32956XUUTG |
| 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 | 11.024 in |
|---|---|
| Outer diameter D | 14.961 in |
| Width B | 2.5 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 50 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) | 29 of 37 |
| Bore above smallest 32900-series size | 245 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32956XUUTG | 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 32956XUUTG model number is decoded
NTN supplies this 280 mm bore tapered roller position as 32956XUUTG: one cone assembly, one cup, line-contact rollers and a steel cage, rated 930 kN basic dynamic and 1520 kN static on the extra-light thin-section 32900 family. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 32956XUUTG resolves to 280 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 50.0 mm radial section carries the roller complement across the 280–380 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. The fatigue load limit Pu printed for 32956XUUTG is 129 kN; in the adjusted-life equation that is the equivalent-load floor below which high reliability is expected even under contamination. After mounting check the contact pattern with marking blue: a pattern biased to the large or small roller end means the 280 mm pair is misadjusted and the 63.5 mm T set will edge-load in service.
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
- 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
- false brinelling on a stationary paired set exposed to external vibration
Selection pitfalls — read before you substitute
- At 280 mm bore the 32956XUUTG 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 930 kN C level.
- The thin 63.5 mm section of 32956XUUTG is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 280 mm bore smears the roller ends against the rib.
- The 50.0 mm section leaves little room for an oversized shaft fillet; check the mounting-chamfer table for 32956XUUTG or the ring will bottom out on the radius instead of the shoulder face.
- ISO 355 makes the 280×380 mm envelope interchangeable but not the ratings: NTN prints 930/1520 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- The U/UTG/X/C/CA/D suffix variants of a base number share the bore but not the article: ordering 32956XUUTG by size alone can deliver the wrong contact-angle execution for a pinion position.
- The 930/1520 kN ratings and 129 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32956XUUTG (ISO 355 4EC); 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 32956XUUTG?
32956XUUTG is a metric 4T tapered roller bearing to ISO 355: 280 mm bore, 380 mm outside diameter and 63.5 mm assembled width T (11.024 × 14.961 × 2.5 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 930 kN, C0 1520 kN, Pu 129 kN, grease limiting speed 790 r/min, oil speed 1,100 r/min, mass about 19900 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32956XUUTG?
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 (32956XUUTG); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32956XUUTG designation encode the 280 mm bore and what is 4EC?
last two digits 56 are the ISO bore code, ×5 = 280 mm (codes 00–03 use the 10/12/15/17 exception table). The 380 mm OD and 63.5 mm assembled T follow the ISO 355 dimension-series plan. 4EC 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 32956XUUTG list two speeds, 790 and 1,100 r/min?
The lower figure, 790 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32956XUUTG at 1,100 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32956XUUTG mean?
Suffix reading on 32956XUUTG: the XUUTG suffix marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design for longer life inside the unchanged ISO 355 envelope; XU combines the X ISO boundary section with the U uprated internal design; 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.