323088UTG bearing: complete specifications & equivalents
The 323088UTG is a ANSI ABMA 19.2 radial bearing sized 440 x 650 x 157 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 440 mm |
| Outer diameter D | 650 mm |
| Width B | 157 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 3350 kN |
| Basic static load rating C0 | 5450 kN |
| Fatigue load limit Pu | 400 kN |
| Limiting speed (mechanical) | 370 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 180000 g |
| Manufacturer designation | NTN 4T-323088UTG |
| Standard | ANSI ABMA 19.2 |
| Catalog version | NTN 2203E 2026-09-25 |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN 2203E 2026-09-25) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN 2203E 2026-09-25); 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 & 4t-432-series range
| Bore d | 17.323 in |
|---|---|
| Outer diameter D | 25.591 in |
| Width B | 6.181 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 105 mm |
| Smallest bore in 4t-432-series | 40 mm |
| Largest outer diameter in 4t-432-series | 790 mm |
| Width range across 4t-432-series | 46–266 mm |
| Bore position in 4t-432-series (smallest first) | 36 of 39 |
| Bore above smallest 4t-432-series size | 400 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 323088UTG | 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 323088UTG model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323088UTG denotes the heavy-duty 432-family TDO double-row series — a 440 mm bore double-row tapered unit rated 3350 kN basic dynamic and 5450 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-323088UTG integrates both rows in one article: the 157 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 370 r/min limiting speed must reach both roller rows; sustaining 520 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-323088UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-323088UTG; the double cup must seat square across its full 157 mm width.
Typical equipment & failure modes
Common applications
- cement-plant mill and kiln drive trains
- port-crane hoist and luffing gearboxes
- heavy press and forging-machine drives
- large shredder and recycler main shafts
Known failure patterns
- roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant
- brinelling of both rows from a mounting blow transmitted through the roller complements
- preload loss and hammering noise when the cup clamping loosens and the unit gains axial float
- cage fatigue after continuous running near the grease limiting speed without oil cooling
- thermal distress when the oil supply sized for one row starves the second row
Selection pitfalls — read before you substitute
- At 440 mm bore the 4T-323088UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3350 kN C level.
- The 432 heavy plan gives 4T-323088UTG its 157 mm width and 3350 kN rating at the 440 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 400 kN Cu.
- Open 4T-323088UTG units have no seals: the housing must seal both rows or the 370 r/min grease figure is meaningless once contamination enters.
- The internal clearance of 4T-323088UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.
- Never interchange a TDO double-row unit with two single-row bearings of similar size: the 157 mm width, load spread and clearance logic of 4T-323088UTG are unit-specific.
- The 3350/5450 kN ratings and 400 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323088UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 4T-323088UTG?
4T-323088UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 440 mm bore, 650 mm outside diameter and 157 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3350 kN, C0 5450 kN, Cu 400 kN, grease limiting speed 370 r/min, oil speed 520 r/min, mass about 180 kg. It is an open, preset-clearance unit with pressed-steel cages.
What is the difference between the NTN 430 and 432 double-row series at 440 mm bore?
Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323088UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family).
Can the internal clearance of 4T-323088UTG be adjusted at mounting?
No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 157 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row.
What do the suffix letters on 323088UTG mean?
Suffix reading on 323088UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles.
Why does 4T-323088UTG list two speeds, 370 and 520 r/min?
The lower figure, 370 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323088UTG at 520 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN 2203E 2026-09-25 on 2026-10-01. Read our editorial & correction policy.