323144UTG bearing: complete specifications & equivalents
The 323144UTG is a ANSI ABMA 19.2 radial bearing sized 220 x 370 x 120 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 220 mm |
| Outer diameter D | 370 mm |
| Width B | 120 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 1570 kN |
| Basic static load rating C0 | 2260 kN |
| Fatigue load limit Pu | 199 kN |
| Limiting speed (mechanical) | 770 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 52200 g |
| Manufacturer designation | NTN 4T-323144UTG |
| 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 | 8.661 in |
|---|---|
| Outer diameter D | 14.567 in |
| Width B | 4.724 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 75 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) | 25 of 39 |
| Bore above smallest 4t-432-series size | 180 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 323144UTG | 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 323144UTG model number is decoded
NTN supplies this 220 mm shaft position as 4T-323144UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 120 mm. Reading the designation: the last two digits 44 are the bore code, ×5 = 220 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. Selection: C 1570 kN against C0 2260 kN gives a C0/C ratio of 1.44; the two rows of 4T-323144UTG share the combined load as one bearing position. The internal clearance of 4T-323144UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 120 mm overall width is the finished dimension. Mount 4T-323144UTG 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
- power-plant mill and fan shafts
- rolling-mill roll-neck and pinion-stand positions
- mine hoist and dragline drum shafts
- cement-plant mill and kiln drive trains
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
- indentation of both raceways by hard particles in an open, unsealed arrangement
Selection pitfalls — read before you substitute
- At 220 mm bore the 4T-323144UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1570 kN C level.
- The 432 heavy plan gives 4T-323144UTG its 120 mm width and 1570 kN rating at the 220 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 199 kN Cu.
- Never interchange a TDO double-row unit with two single-row bearings of similar size: the 120 mm width, load spread and clearance logic of 4T-323144UTG are unit-specific.
- Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323144UTG feeds the two roller complements evenly; a single-side feed starves the far row.
- At inspection do not mix the cone assemblies of 4T-323144UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.
- The 1570/2260 kN ratings and 199 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323144UTG; 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-323144UTG?
4T-323144UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 220 mm bore, 370 mm outside diameter and 120 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1570 kN, C0 2260 kN, Cu 199 kN, grease limiting speed 770 r/min, oil speed 1,100 r/min, mass about 52.2 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 220 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-323144UTG 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-323144UTG 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 120 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 323144UTG mean?
Suffix reading on 323144UTG: 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-323144UTG list two speeds, 770 and 1,100 r/min?
The lower figure, 770 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323144UTG at 1,100 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.