32068UTG bearing: complete specifications & equivalents
The 32068UTG is a ISO 355 radial bearing sized 340 x 520 x 112 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 | 520 mm |
| Width B | 112 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 2120 kN |
| Basic static load rating C0 | 3150 kN |
| Fatigue load limit Pu | 249 kN |
| Limiting speed (mechanical) | 590 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 78500 g |
| Manufacturer designation | NTN 32068UTG |
| Standard | ISO 355 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); 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 & 32000-series range
| Bore d | 13.386 in |
|---|---|
| Outer diameter D | 20.472 in |
| Width B | 4.409 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 90 mm |
| Smallest bore in 32000-series | 20 mm |
| Largest outer diameter in 32000-series | 650 mm |
| Width range across 32000-series | 15–130 mm |
| Bore position in 32000-series (smallest first) | 38 of 43 |
| Bore above smallest 32000-series size | 320 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32068UTG | 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 32068UTG model number is decoded
For a 340 mm shaft with a thrust component, NTN lists 32068UTG, a metric 4T tapered roller bearing of 2120 kN C and 3150 kN C0 inside the 520 mm OD, 112 mm-wide assembled set. NTN also quotes this bearing with its ISO 355 dimension-series abbreviation which is the maker-neutral cross-reference for the 340×520 mm envelope; 4T is NTN's own tapered-roller brand mark on the parts. Individually mounted, 32068UTG takes axial force in one direction only; two bearings are arranged face-to-face (X) or back-to-back (O) according to the moment stiffness and misalignment the shaft requires. Selection: C 2120 kN against C0 3150 kN gives a C0/C ratio of 1.49 for the 340 mm bore, and the equivalent combined load must keep below the rating at the target L10 with the pair counted as one unit. Fillet radii must clear the ring chamfers of the 520 mm cup and 340 mm cone; use undercut shoulders so the rings seat fully rather than bridging on a shaft radius.
Typical equipment & failure modes
Common applications
- cement-plant kiln and mill drive trains
- rolling-mill roll-neck and gearbox positions
- large crusher and SAG/AG-mill drive shafts
- wind-turbine gearbox and main-shaft arrangements
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- fretting corrosion on a loose cone seat that creeps under rotating load
Selection pitfalls — read before you substitute
- At 340 mm bore the 32068UTG set is adjusted with hydraulic nuts on large mill and wind positions; follow the drive-up angle/end-play procedure, because manual torque methods cannot control preload at the 2120 kN C level.
- The thin 112 mm section of 32068UTG is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 340 mm bore smears the roller ends against the rib.
- Grease packs must leave free volume in the 112 mm-wide set; over-greasing a paired bearing churning at the 840 r/min oil-band speed raises temperature and destroys the preload setting.
- Replacing one half of an adjusted pair without resetting end play negates the 112 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- Never fit the 340 mm cone by hammering the 520 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- The 2120/3150 kN ratings and 249 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32068UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, adjustment and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 32068UTG?
32068UTG is a metric 4T tapered roller bearing to ISO 355: 340 mm bore, 520 mm outside diameter and 112 mm assembled width T (13.386 × 20.472 × 4.409 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 2120 kN, C0 3150 kN, Pu 249 kN, grease limiting speed 590 r/min, oil speed 840 r/min, mass about 78500 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32068UTG?
4T is NTN's tapered roller bearing brand mark, stamped on the cone and cup in the factory. It identifies the NTN 4T programme and is not a dimension, so the catalogue and this page list the bare ISO 355 number (32068UTG); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32068UTG designation encode the 340 mm bore?
last two digits 68 are the ISO bore code, ×5 = 340 mm (codes 00–03 use the 10/12/15/17 exception table). The 520 mm OD and 112 mm assembled T follow the ISO 355 dimension-series plan.
Why does 32068UTG list two speeds, 590 and 840 r/min?
The lower figure, 590 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32068UTG at 840 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32068UTG mean?
Suffix reading on 32068UTG: the UTG suffix marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design for longer life inside the unchanged ISO 355 envelope; the suffix is part of the order number and the variants are not interchangeable articles.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.