323064UTG bearing: complete specifications & equivalents
The 323064UTG is a ANSI ABMA 19.2 radial bearing sized 320 x 480 x 121 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 320 mm |
| Outer diameter D | 480 mm |
| Width B | 121 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 2030 kN |
| Basic static load rating C0 | 3100 kN |
| Fatigue load limit Pu | 247 kN |
| Limiting speed (mechanical) | 530 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 73400 g |
| Manufacturer designation | NTN 4T-323064UTG |
| 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 | 12.598 in |
|---|---|
| Outer diameter D | 18.898 in |
| Width B | 4.764 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 80 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) | 30 of 39 |
| Bore above smallest 4t-432-series size | 280 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 323064UTG | 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 323064UTG model number is decoded
NTN supplies this 320 mm shaft position as 4T-323064UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 121 mm. Reading the designation: the last two digits 64 are the bore code, ×5 = 320 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Axial capacity is bidirectional because the rows are opposed: 4T-323064UTG locates the shaft in both directions with C0 3100 kN behind the static check of the more heavily loaded row. The internal clearance of 4T-323064UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 121 mm overall width is the finished dimension. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-323064UTG are ground as a unit.
Typical equipment & failure modes
Common applications
- rolling-mill roll-neck and pinion-stand positions
- mine hoist and dragline drum shafts
- cement-plant mill and kiln drive trains
- port-crane hoist and luffing gearboxes
Known failure patterns
- roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant
- one-row flaking when a bent shaft concentrates the combined load on a single row of the pair
- overheated running after a field attempt to "tighten up" the factory-set internal clearance
- cage damage when the unit is lifted by one cone instead of the double cup during fitting
- indentation of both raceways by hard particles in an open, unsealed arrangement
Selection pitfalls — read before you substitute
- At 320 mm bore the 4T-323064UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2030 kN C level.
- The 432 heavy plan gives 4T-323064UTG its 121 mm width and 2030 kN rating at the 320 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 247 kN Cu.
- The internal clearance of 4T-323064UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.
- The 2030 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.
- Open 4T-323064UTG units have no seals: the housing must seal both rows or the 530 r/min grease figure is meaningless once contamination enters.
- The 2030/3100 kN ratings and 247 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323064UTG; 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-323064UTG?
4T-323064UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 320 mm bore, 480 mm outside diameter and 121 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2030 kN, C0 3100 kN, Cu 247 kN, grease limiting speed 530 r/min, oil speed 750 r/min, mass about 73.4 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 320 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-323064UTG 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-323064UTG 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 121 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 323064UTG mean?
Suffix reading on 323064UTG: 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-323064UTG list two speeds, 530 and 750 r/min?
The lower figure, 530 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323064UTG at 750 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.