33016U bearing: complete specifications & equivalents
The 33016U is a ISO 355 radial bearing sized 80 x 125 x 36 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 80 mm |
| Outer diameter D | 125 mm |
| Width B | 36 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 192 kN |
| Basic static load rating C0 | 284 kN |
| Fatigue load limit Pu | 34.5 kN |
| Limiting speed (mechanical) | 2800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1610 g |
| Manufacturer designation | NTN 33016U |
| 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 & 33000-series range
| Bore d | 3.15 in |
|---|---|
| Outer diameter D | 4.921 in |
| Width B | 1.417 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 22.5 mm |
| Smallest bore in 33000-series | 25 mm |
| Largest outer diameter in 33000-series | 225 mm |
| Width range across 33000-series | 17–59 mm |
| Bore position in 33000-series (smallest first) | 14 of 24 |
| Bore above smallest 33000-series size | 55 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33016U | 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 33016U model number is decoded
33016U belongs to the NTN metric 4T tapered roller range (slim 33000 family); the open bearing leaves sealing to the application and is normally ordered and mounted as an adjustable matched pair. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 33016U resolves to 80 mm bore; the NTN factory mark 4T is stamped on cone and cup but is a brand mark, not a size code, so the catalogue sku is printed without it. NTN adjusts these bearings by cup or cone position rather than shipping a preloaded set; the mounting drawing must state end play or preload for 33016U, since running clearance is set during assembly. Catalogue mass of the 33016U set is 1610 g (0.063 lb cone + cup); abutment and shaft shoulder design must carry that mass square to the axis. Fillet radii must clear the ring chamfers of the 125 mm cup and 80 mm cone; use undercut shoulders so the rings seat fully rather than bridging on a shaft radius.
Typical equipment & failure modes
Common applications
- paper-machine press-section rolls
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
- rolling-mill auxiliary and pinion-stand shafts
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- water-induced pitting when the open bearing is exposed to washdown without external seals
Selection pitfalls — read before you substitute
- Mount the 80 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 1610 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The thin 36 mm section of 33016U is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 80 mm bore smears the roller ends against the rib.
- The U/UTG/X/C/CA/D suffix variants of a base number share the bore but not the article: ordering 33016U by size alone can deliver the wrong contact-angle execution for a pinion position.
- The U/UTG/X/C/CA/D suffix variants of a base number share the bore but not the article: ordering 33016U by size alone can deliver the wrong contact-angle execution for a pinion position.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 80 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- The 192/284 kN ratings and 34.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33016U (ISO 355 2CE); 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 33016U?
33016U is a metric 4T tapered roller bearing to ISO 355: 80 mm bore, 125 mm outside diameter and 36 mm assembled width T (3.15 × 4.921 × 1.417 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 192 kN, C0 284 kN, Pu 34.5 kN, grease limiting speed 2,800 r/min, oil speed 3,700 r/min, mass about 1610 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33016U?
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 (33016U); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33016U designation encode the 80 mm bore and what is 2CE?
last two digits 16 are the ISO bore code, ×5 = 80 mm (codes 00–03 use the 10/12/15/17 exception table). The 125 mm OD and 36 mm assembled T follow the ISO 355 dimension-series plan. 2CE 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 33016U list two speeds, 2,800 and 3,700 r/min?
The lower figure, 2,800 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33016U at 3,700 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33016U mean?
Suffix reading on 33016U: 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.