33015U bearing: complete specifications & equivalents
The 33015U is a ISO 355 radial bearing sized 75 x 115 x 31 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 75 mm |
| Outer diameter D | 115 mm |
| Width B | 31 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 123 kN |
| Basic static load rating C0 | 186 kN |
| Fatigue load limit Pu | 22.7 kN |
| Limiting speed (mechanical) | 3000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1110 g |
| Manufacturer designation | NTN 33015U |
| 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 | 2.953 in |
|---|---|
| Outer diameter D | 4.528 in |
| Width B | 1.22 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 20 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) | 13 of 24 |
| Bore above smallest 33000-series size | 50 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33015U | 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 33015U model number is decoded
33015U is the NTN 4T catalogue entry for a 75×115×31 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. NTN also quotes this bearing with its ISO 355 dimension-series abbreviation, 2CE, which is the maker-neutral cross-reference for the 75×115 mm envelope; 4T is NTN's own tapered-roller brand mark on the parts. The printed contact-angle geometry gives the slim 33000 family its characteristic load split — at 123/186 kN (C/C0) the static rating is about 1.51× C, typical of tapered bearings proportioned for heavy combined duty. The fatigue load limit Pu printed for 33015U is 22.7 kN; in the adjusted-life equation that is the equivalent-load floor below which high reliability is expected even under contamination. When pairing 33015U with a second tapered bearing, keep the matched arrangement clean: a single stray grit particle between cup and housing changes preload faster than the adjustment range can correct.
Typical equipment & failure modes
Common applications
- marine winch and deck-machinery shafts
- paper-machine press-section rolls
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- cage damage from a mounting blow delivered through the roller complement instead of the ring face
- fretting corrosion on a loose cone seat that creeps under rotating load
Selection pitfalls — read before you substitute
- Mount the 75 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 1110 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The thin 31 mm section of 33015U is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 75 mm bore smears the roller ends against the rib.
- Replacing one half of an adjusted pair without resetting end play negates the 31 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 75 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- Minimum load matters at high speed: an unloaded 33015U at a large fraction of 3,000 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 123/186 kN ratings and 22.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33015U (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 33015U?
33015U is a metric 4T tapered roller bearing to ISO 355: 75 mm bore, 115 mm outside diameter and 31 mm assembled width T (2.953 × 4.528 × 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 123 kN, C0 186 kN, Pu 22.7 kN, grease limiting speed 3,000 r/min, oil speed 4,000 r/min, mass about 1110 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33015U?
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 (33015U); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33015U designation encode the 75 mm bore and what is 2CE?
last two digits 15 are the ISO bore code, ×5 = 75 mm (codes 00–03 use the 10/12/15/17 exception table). The 115 mm OD and 31 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 33015U list two speeds, 3,000 and 4,000 r/min?
The lower figure, 3,000 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33015U at 4,000 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33015U mean?
Suffix reading on 33015U: 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.