32976UTG bearing: complete specifications & equivalents
The 32976UTG is a ISO 355 radial bearing sized 380 x 520 x 87 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 380 mm |
| Outer diameter D | 520 mm |
| Width B | 87 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1460 kN |
| Basic static load rating C0 | 2500 kN |
| Fatigue load limit Pu | 194 kN |
| Limiting speed (mechanical) | 550 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 51300 g |
| Manufacturer designation | NTN 32976UTG |
| 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 | 14.961 in |
|---|---|
| Outer diameter D | 20.472 in |
| Width B | 3.425 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 70 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) | 34 of 37 |
| Bore above smallest 32900-series size | 345 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32976UTG | 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 32976UTG model number is decoded
The NTN 2203E table prints 32976UTG in the extra-light thin-section 32900 family: 380 mm bore, 520 mm cup OD, 87 mm T, with a grease limiting speed of 550 r/min and an oil-lubricated ceiling of 790 r/min. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 32976UTG resolves to 380 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. 2203E lists two speed ceilings for 32976UTG: 550 r/min with grease lubrication (the limiting speed) and 790 r/min with oil, the higher oil value reflecting better heat removal from the cone rib. The two speed columns differ by a factor of .70 (grease/limiting 550 vs oil 790 r/min); heat generation at the cone rib decides which lubrication a real 32976UTG arrangement can sustain. After mounting check the contact pattern with marking blue: a pattern biased to the large or small roller end means the 380 mm pair is misadjusted and the 87 mm T set will edge-load in service.
Typical equipment & failure modes
Common applications
- large crusher and SAG/AG-mill drive shafts
- wind-turbine gearbox and main-shaft arrangements
- offshore crane and drawworks drums
- heavy haul railway traction gearboxes
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- 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
- fretting corrosion on a loose cone seat that creeps under rotating load
Selection pitfalls — read before you substitute
- At 380 mm bore the 32976UTG 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 1460 kN C level.
- The thin 87 mm section of 32976UTG is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 380 mm bore smears the roller ends against the rib.
- Replacing one half of an adjusted pair without resetting end play negates the 87 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- Never fit the 380 mm cone by hammering the 520 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Grease packs must leave free volume in the 87 mm-wide set; over-greasing a paired bearing churning at the 790 r/min oil-band speed raises temperature and destroys the preload setting.
- The 1460/2500 kN ratings and 194 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32976UTG; 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 32976UTG?
32976UTG is a metric 4T tapered roller bearing to ISO 355: 380 mm bore, 520 mm outside diameter and 87 mm assembled width T (14.961 × 20.472 × 3.425 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1460 kN, C0 2500 kN, Pu 194 kN, grease limiting speed 550 r/min, oil speed 790 r/min, mass about 51300 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32976UTG?
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 (32976UTG); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32976UTG designation encode the 380 mm bore?
last two digits 76 are the ISO bore code, ×5 = 380 mm (codes 00–03 use the 10/12/15/17 exception table). The 520 mm OD and 87 mm assembled T follow the ISO 355 dimension-series plan.
Why does 32976UTG list two speeds, 550 and 790 r/min?
The lower figure, 550 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32976UTG at 790 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32976UTG mean?
Suffix reading on 32976UTG: the UTG suffix marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design for longer life inside the unchanged ISO 355 envelope; 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.