30326UUTG bearing: complete specifications & equivalents
The 30326UUTG is a ISO 355 radial bearing sized 130 x 280 x 63.75 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 130 mm |
| Outer diameter D | 280 mm |
| Width B | 63.75 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 830 kN |
| Basic static load rating C0 | 830 kN |
| Fatigue load limit Pu | 81 kN |
| Limiting speed (mechanical) | 1400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 17400 g |
| Manufacturer designation | NTN 30326UUTG |
| 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 | 5.118 in |
|---|---|
| Outer diameter D | 11.024 in |
| Width B | 2.51 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 75 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) | 23 of 32 |
| Bore above smallest 30300-series size | 115 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30326UUTG | 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 30326UUTG model number is decoded
30326UUTG is a metric single-row tapered roller bearing in the NTN 4T programme: a pressed-steel cage guides profiled rollers between a separable cone and cup on the 130×280 mm ISO 355 envelope, with 63.75 mm overall assembled width T. Digit by digit, the bare number identifies the large-OD 30300 family with the steeper contact angle and a bore code resolving to 130 mm; 280 mm OD and 63.75 mm assembled T are the matching ISO 355 boundary dimensions shared with other makers of the same dimension series. 2203E lists two speed ceilings for 30326UUTG: 1,400 r/min with grease lubrication (the limiting speed) and 2,000 r/min with oil, the higher oil value reflecting better heat removal from the cone rib. Catalogue mass of the 30326UUTG set is 17400 g (0.685 lb cone + cup); abutment and shaft shoulder design must carry that mass square to the axis. When pairing 30326UUTG with a second tapered bearing, keep the matched arrangement clean: a single stray grit particle between cup and housing changes preload faster than the adjustment range can correct.
Typical equipment & failure modes
Common applications
- heavy haul railway traction gearboxes
- large marine propulsion reduction gears
- cement-plant kiln and mill drive trains
- rolling-mill roll-neck and gearbox positions
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- indentation of the raceways by hard particles in unsealed open arrangements
Selection pitfalls — read before you substitute
- At 130 mm bore the 30326UUTG 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 830 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 130 mm bore; do not swap to the lighter family without re-checking the 1,400 r/min grease limit and the thrust load split.
- Replacing one half of an adjusted pair without resetting end play negates the 63.75 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 130×280 mm envelope interchangeable but not the ratings: NTN prints 830/830 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- Grease packs must leave free volume in the 63.75 mm-wide set; over-greasing a paired bearing churning at the 2,000 r/min oil-band speed raises temperature and destroys the preload setting.
- The 830/830 kN ratings and 81 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30326UUTG (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 30326UUTG?
30326UUTG is a metric 4T tapered roller bearing to ISO 355: 130 mm bore, 280 mm outside diameter and 63.75 mm assembled width T (5.118 × 11.024 × 2.51 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 830 kN, C0 830 kN, Pu 81 kN, grease limiting speed 1,400 r/min, oil speed 2,000 r/min, mass about 17400 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30326UUTG?
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 (30326UUTG); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30326UUTG designation encode the 130 mm bore and what is 2GB?
last two digits 26 are the ISO bore code, ×5 = 130 mm (codes 00–03 use the 10/12/15/17 exception table). The 280 mm OD and 63.75 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 30326UUTG list two speeds, 1,400 and 2,000 r/min?
The lower figure, 1,400 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 30326UUTG at 2,000 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 30326UUTG mean?
Suffix reading on 30326UUTG: 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.