33114U bearing: complete specifications & equivalents
The 33114U is a ISO 355 radial bearing sized 70 x 120 x 37 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 70 mm |
| Outer diameter D | 120 mm |
| Width B | 37 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 190 kN |
| Basic static load rating C0 | 251 kN |
| Fatigue load limit Pu | 30.5 kN |
| Limiting speed (mechanical) | 3100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1680 g |
| Manufacturer designation | NTN 33114U |
| 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 & 33100-series range
| Bore d | 2.756 in |
|---|---|
| Outer diameter D | 4.724 in |
| Width B | 1.457 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 33100-series | 40 mm |
| Largest outer diameter in 33100-series | 200 mm |
| Width range across 33100-series | 26–62 mm |
| Bore position in 33100-series (smallest first) | 7 of 13 |
| Bore above smallest 33100-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33114U | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 33114U model number is decoded
For a 70 mm shaft with a thrust component, NTN lists 33114U, a metric 4T tapered roller bearing of 190 kN C and 251 kN C0 inside the 120 mm OD, 37 mm-wide assembled set. The last two digits 14 are the ISO bore code, ×5 = 70 mm (codes 00–03 use the 10/12/15/17 exception table) under the ISO 355 numbering; the 37 mm value printed here is T, the width of the fully assembled cone-plus-cup set, not the inner-ring width alone. The pressed-steel cage and surface-finished roller ends are standard 4T execution; ULTAGE-marked variants use upgraded material and internal geometry aimed at longer rating life with the same ISO 355 envelope. The fatigue load limit Pu printed for 33114U is 30.5 kN; in the adjusted-life equation that is the equivalent-load floor below which high reliability is expected even under contamination. Mount the 70 mm-bore cone on the shaft first (induction heat, max 120 °C), fit the cup square in its housing, then set preload or end play; never drive the cup home through the rollers of 33114U.
Typical equipment & failure modes
Common applications
- large conveyor and bucket-elevator pulleys
- mineral-processing feeder and crusher auxiliaries
- marine winch and deck-machinery shafts
- paper-machine press-section rolls
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
- indentation of the raceways by hard particles in unsealed open arrangements
Selection pitfalls — read before you substitute
- Mount the 70 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 1680 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The light-wide 33100 family at 70 mm bore (120×37 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 4,100 r/min oil ceiling.
- Never fit the 70 mm cone by hammering the 120 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Grease packs must leave free volume in the 37 mm-wide set; over-greasing a paired bearing churning at the 4,100 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 37 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- The 190/251 kN ratings and 30.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33114U (ISO 355 3DE); 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 33114U?
33114U is a metric 4T tapered roller bearing to ISO 355: 70 mm bore, 120 mm outside diameter and 37 mm assembled width T (2.756 × 4.724 × 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 190 kN, C0 251 kN, Pu 30.5 kN, grease limiting speed 3,100 r/min, oil speed 4,100 r/min, mass about 1680 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33114U?
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 (33114U); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33114U designation encode the 70 mm bore and what is 3DE?
last two digits 14 are the ISO bore code, ×5 = 70 mm (codes 00–03 use the 10/12/15/17 exception table). The 120 mm OD and 37 mm assembled T follow the ISO 355 dimension-series plan. 3DE is the maker-neutral ISO 355 abbreviation for this dimension series (the same code other manufacturers print); 4T is NTN's own brand mark.
Why does 33114U list two speeds, 3,100 and 4,100 r/min?
The lower figure, 3,100 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33114U at 4,100 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33114U mean?
Suffix reading on 33114U: U marks the reinforced/uprated internal design of the bare number, a separate order number with higher load capacity than the basic execution; 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.