32944XUUTG bearing: complete specifications & equivalents
The 32944XUUTG is a ISO 355 radial bearing sized 220 x 300 x 51 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 220 mm |
| Outer diameter D | 300 mm |
| Width B | 51 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 615 kN |
| Basic static load rating C0 | 950 kN |
| Fatigue load limit Pu | 87 kN |
| Limiting speed (mechanical) | 1000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 9980 g |
| Manufacturer designation | NTN 32944XUUTG |
| 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 | 8.661 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 2.008 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 40 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) | 26 of 37 |
| Bore above smallest 32900-series size | 185 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32944XUUTG | 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 32944XUUTG model number is decoded
32944XUUTG is the NTN 4T catalogue entry for a 220×300×51 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 32944XUUTG by the metric ISO 355 number (ISO series abbreviation 3EC): 220 mm bore, 300 mm OD. The 40.0 mm radial section carries the roller complement across the 220–300 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 32944XUUTG is 87 kN; in the adjusted-life equation that is the equivalent-load floor below which high reliability is expected even under contamination. With a rotating shaft a m6/n6 shaft seat and a press-fit cup are typical catalogue practice for 32944XUUTG; reverse the logic if the cup rotates, and re-verify against load direction and magnitude.
Typical equipment & failure modes
Common applications
- wind-turbine gearbox and main-shaft arrangements
- offshore crane and drawworks drums
- heavy haul railway traction gearboxes
- large marine propulsion reduction gears
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- cage damage from a mounting blow delivered through the roller complement instead of the ring face
- water-induced pitting when the open bearing is exposed to washdown without external seals
Selection pitfalls — read before you substitute
- At 220 mm bore the 32944XUUTG 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 615 kN C level.
- The thin 51 mm section of 32944XUUTG is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 220 mm bore smears the roller ends against the rib.
- Do not confuse T (51 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.
- ISO 355 makes the 220×300 mm envelope interchangeable but not the ratings: NTN prints 615/950 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 32944XUUTG by size alone can deliver the wrong contact-angle execution for a pinion position.
- The 615/950 kN ratings and 87 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32944XUUTG (ISO 355 3EC); 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 32944XUUTG?
32944XUUTG is a metric 4T tapered roller bearing to ISO 355: 220 mm bore, 300 mm outside diameter and 51 mm assembled width T (8.661 × 11.811 × 2.008 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 615 kN, C0 950 kN, Pu 87 kN, grease limiting speed 1,000 r/min, oil speed 1,500 r/min, mass about 9980 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32944XUUTG?
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 (32944XUUTG); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32944XUUTG designation encode the 220 mm bore and what is 3EC?
last two digits 44 are the ISO bore code, ×5 = 220 mm (codes 00–03 use the 10/12/15/17 exception table). The 300 mm OD and 51 mm assembled T follow the ISO 355 dimension-series plan. 3EC 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 32944XUUTG list two speeds, 1,000 and 1,500 r/min?
The lower figure, 1,000 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32944XUUTG at 1,500 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32944XUUTG mean?
Suffix reading on 32944XUUTG: 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.