323168UTG bearing: complete specifications & equivalents
The 323168UTG is a ANSI ABMA 19.2 radial bearing sized 340 x 580 x 190 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 340 mm |
| Outer diameter D | 580 mm |
| Width B | 190 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 4300 kN |
| Basic static load rating C0 | 6500 kN |
| Fatigue load limit Pu | 500 kN |
| Limiting speed (mechanical) | 460 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 210000 g |
| Manufacturer designation | NTN 4T-323168UTG |
| 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 | 13.386 in |
|---|---|
| Outer diameter D | 22.835 in |
| Width B | 7.48 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 120 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) | 31 of 39 |
| Bore above smallest 4t-432-series size | 300 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 323168UTG | 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 323168UTG model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323168UTG denotes the heavy-duty 432-family TDO double-row series — a 340 mm bore double-row tapered unit rated 4300 kN basic dynamic and 6500 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-323168UTG integrates both rows in one article: the 190 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 460 r/min limiting speed must reach both roller rows; sustaining 660 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-323168UTG 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 340 mm shaft. With a rotating shaft a m6/n6 seat on the 340 mm journal and a located cup in the housing are typical practice for 4T-323168UTG.
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
- pressed-steel cage pocket wear from roller skid at light load and high speed
- false brinelling on a stored or standby unit exposed to vibration
Selection pitfalls — read before you substitute
- At 340 mm bore the 4T-323168UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4300 kN C level.
- The 432 heavy plan gives 4T-323168UTG its 190 mm width and 4300 kN rating at the 340 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 500 kN Cu.
- The 4300 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.
- The internal clearance of 4T-323168UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.
- Order by the full 323168UTG code including suffixes — U, X, DX, E1 and UTG variants share the 340 mm bore but are different articles with different internal geometry.
- The 4300/6500 kN ratings and 500 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323168UTG; 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-323168UTG?
4T-323168UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 340 mm bore, 580 mm outside diameter and 190 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4300 kN, C0 6500 kN, Cu 500 kN, grease limiting speed 460 r/min, oil speed 660 r/min, mass about 210 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 340 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-323168UTG 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-323168UTG 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 190 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 323168UTG mean?
Suffix reading on 323168UTG: 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-323168UTG list two speeds, 460 and 660 r/min?
The lower figure, 460 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323168UTG at 660 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.