30252UTG bearing: complete specifications & equivalents
The 30252UTG is a ISO 355 radial bearing sized 260 x 480 x 89 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 260 mm |
| Outer diameter D | 480 mm |
| Width B | 89 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1500 kN |
| Basic static load rating C0 | 1810 kN |
| Fatigue load limit Pu | 149 kN |
| Limiting speed (mechanical) | 690 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 63400 g |
| Manufacturer designation | NTN 30252UTG |
| 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 & 30200-series range
| Bore d | 10.236 in |
|---|---|
| Outer diameter D | 18.898 in |
| Width B | 3.504 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 110 mm |
| Smallest bore in 30200-series | 15 mm |
| Largest outer diameter in 30200-series | 580 mm |
| Width range across 30200-series | 11.75–104 mm |
| Bore position in 30200-series (smallest first) | 34 of 37 |
| Bore above smallest 30200-series size | 245 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30252UTG | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 30252UTG model number is decoded
NTN supplies this 260 mm bore tapered roller position as 30252UTG: one cone assembly, one cup, line-contact rollers and a steel cage, rated 1500 kN basic dynamic and 1810 kN static on the standard-section 30200 family. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 30252UTG resolves to 260 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 110.0 mm radial section carries the roller complement across the 260–480 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. Selection: C 1500 kN against C0 1810 kN gives a C0/C ratio of 1.21 for the 260 mm bore, and the equivalent combined load must keep below the rating at the target L10 with the pair counted as one unit. Open 4T bearings need application seals; without them the grease at the cone rib of 30252UTG washes out and the rib/roller-end contact smears on the first wet or dusty shift.
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
- 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 fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- edge loading when shaft deflection exceeds the few arc-minutes of misalignment the adjusted pair allows
Selection pitfalls — read before you substitute
- At 260 mm bore the 30252UTG 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 1500 kN C level.
- The standard-section 30200 family at 260 mm bore (480×89 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 990 r/min oil ceiling.
- ISO 355 makes the 260×480 mm envelope interchangeable but not the ratings: NTN prints 1500/1810 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- ISO 355 makes the 260×480 mm envelope interchangeable but not the ratings: NTN prints 1500/1810 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 30252UTG by size alone can deliver the wrong contact-angle execution for a pinion position.
- The 1500/1810 kN ratings and 149 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30252UTG; 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 30252UTG?
30252UTG is a metric 4T tapered roller bearing to ISO 355: 260 mm bore, 480 mm outside diameter and 89 mm assembled width T (10.236 × 18.898 × 3.504 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1500 kN, C0 1810 kN, Pu 149 kN, grease limiting speed 690 r/min, oil speed 990 r/min, mass about 63400 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30252UTG?
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 (30252UTG); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30252UTG designation encode the 260 mm bore?
last two digits 52 are the ISO bore code, ×5 = 260 mm (codes 00–03 use the 10/12/15/17 exception table). The 480 mm OD and 89 mm assembled T follow the ISO 355 dimension-series plan.
Why does 30252UTG list two speeds, 690 and 990 r/min?
The lower figure, 690 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 30252UTG at 990 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 30252UTG mean?
Suffix reading on 30252UTG: 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.