323148UTG bearing: complete specifications & equivalents
The 323148UTG is a ANSI ABMA 19.2 radial bearing sized 240 x 400 x 128 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 240 mm |
| Outer diameter D | 400 mm |
| Width B | 128 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1790 kN |
| Basic static load rating C0 | 2600 kN |
| Fatigue load limit Pu | 223 kN |
| Limiting speed (mechanical) | 700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 63400 g |
| Manufacturer designation | NTN 4T-323148UTG |
| 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 | 9.449 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 5.039 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) | 26 of 39 |
| Bore above smallest 4t-432-series size | 200 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 323148UTG | 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 323148UTG model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323148UTG denotes the heavy-duty 432-family TDO double-row series — a 240 mm bore double-row tapered unit rated 1790 kN basic dynamic and 2600 kN static. Suffix reading on 323148UTG: 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. Selection: C 1790 kN against C0 2600 kN gives a C0/C ratio of 1.45; the two rows of 4T-323148UTG share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-323148UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 240 mm shaft. Mount 4T-323148UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.
Typical equipment & failure modes
Common applications
- port-crane hoist and luffing gearboxes
- heavy press and forging-machine drives
- large shredder and recycler main shafts
- power-plant mill and fan shafts
Known failure patterns
- roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant
- preload loss and hammering noise when the cup clamping loosens and the unit gains axial float
- brinelling of both rows from a mounting blow transmitted through the roller complements
- pressed-steel cage pocket wear from roller skid at light load and high speed
- water-induced pitting when washdown reaches the open unit without external seals
Selection pitfalls — read before you substitute
- At 240 mm bore the 4T-323148UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1790 kN C level.
- The 432 heavy plan gives 4T-323148UTG its 128 mm width and 1790 kN rating at the 240 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 223 kN Cu.
- Clamping the double cup with a cocked end cover pinches one row: tighten the 400 mm OD clamping uniformly around the circumference.
- Clamping the double cup with a cocked end cover pinches one row: tighten the 400 mm OD clamping uniformly around the circumference.
- Never interchange a TDO double-row unit with two single-row bearings of similar size: the 128 mm width, load spread and clearance logic of 4T-323148UTG are unit-specific.
- The 1790/2600 kN ratings and 223 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323148UTG; 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-323148UTG?
4T-323148UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 400 mm outside diameter and 128 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1790 kN, C0 2600 kN, Cu 223 kN, grease limiting speed 700 r/min, oil speed 1,000 r/min, mass about 63.4 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 240 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-323148UTG 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-323148UTG 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 128 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 323148UTG mean?
Suffix reading on 323148UTG: 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-323148UTG list two speeds, 700 and 1,000 r/min?
The lower figure, 700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323148UTG at 1,000 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.