30330UUTG bearing: complete specifications & equivalents
The 30330UUTG is a ISO 355 radial bearing sized 150 x 320 x 72 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 150 mm |
| Outer diameter D | 320 mm |
| Width B | 72 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1060 kN |
| Basic static load rating C0 | 1070 kN |
| Fatigue load limit Pu | 101 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 25400 g |
| Manufacturer designation | NTN 30330UUTG |
| 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 & 30300-series range
| Bore d | 5.906 in |
|---|---|
| Outer diameter D | 12.598 in |
| Width B | 2.835 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 85 mm |
| Smallest bore in 30300-series | 15 mm |
| Largest outer diameter in 30300-series | 500 mm |
| Width range across 30300-series | 14.25–105 mm |
| Bore position in 30300-series (smallest first) | 25 of 32 |
| Bore above smallest 30300-series size | 135 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30330UUTG | 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 30330UUTG model number is decoded
For a 150 mm shaft with a thrust component, NTN lists 30330UUTG, a metric 4T tapered roller bearing of 1060 kN C and 1070 kN C0 inside the 320 mm OD, 72 mm-wide assembled set. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 30330UUTG by the metric ISO 355 number (ISO series abbreviation 2GB): 150 mm bore, 320 mm OD. NTN adjusts these bearings by cup or cone position rather than shipping a preloaded set; the mounting drawing must state end play or preload for 30330UUTG, since running clearance is set during assembly. The two speed columns differ by a factor of .71 (grease/limiting 1,200 vs oil 1,700 r/min); heat generation at the cone rib decides which lubrication a real 30330UUTG arrangement can sustain. Mount the 150 mm-bore cone on the shaft first (induction heat, max 120 °C), fit the cup square in its housing, then set preload or end play; never drive the cup home through the rollers of 30330UUTG.
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
- indentation of the raceways by hard particles in unsealed open arrangements
Selection pitfalls — read before you substitute
- At 150 mm bore the 30330UUTG 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 1060 kN C level.
- The steeper contact angle of the large-OD 30300 family with the steeper contact angle raises axial capacity but lowers the speed ceiling against a 302/322 bearing at 150 mm bore; do not swap to the lighter family without re-checking the 1,200 r/min grease limit and the thrust load split.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 150 mm shoulder geometry, because retrofitting flips the cups.
- ISO 355 makes the 150×320 mm envelope interchangeable but not the ratings: NTN prints 1060/1070 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 150 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- The 1060/1070 kN ratings and 101 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30330UUTG (ISO 355 2GB); 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 30330UUTG?
30330UUTG is a metric 4T tapered roller bearing to ISO 355: 150 mm bore, 320 mm outside diameter and 72 mm assembled width T (5.906 × 12.598 × 2.835 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1060 kN, C0 1070 kN, Pu 101 kN, grease limiting speed 1,200 r/min, oil speed 1,700 r/min, mass about 25400 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30330UUTG?
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 (30330UUTG); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30330UUTG designation encode the 150 mm bore and what is 2GB?
last two digits 30 are the ISO bore code, ×5 = 150 mm (codes 00–03 use the 10/12/15/17 exception table). The 320 mm OD and 72 mm assembled T follow the ISO 355 dimension-series plan. 2GB 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 30330UUTG list two speeds, 1,200 and 1,700 r/min?
The lower figure, 1,200 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 30330UUTG at 1,700 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 30330UUTG mean?
Suffix reading on 30330UUTG: the UUTG 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.