33212U bearing: complete specifications & equivalents
The 33212U is a ISO 355 radial bearing sized 60 x 110 x 38 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 60 mm |
| Outer diameter D | 110 mm |
| Width B | 38 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 179 kN |
| Basic static load rating C0 | 223 kN |
| Fatigue load limit Pu | 27.1 kN |
| Limiting speed (mechanical) | 3400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1530 g |
| Manufacturer designation | NTN 33212U |
| 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 & 33200-series range
| Bore d | 2.362 in |
|---|---|
| Outer diameter D | 4.331 in |
| Width B | 1.496 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 33200-series | 25 mm |
| Largest outer diameter in 33200-series | 180 mm |
| Width range across 33200-series | 22–63 mm |
| Bore position in 33200-series (smallest first) | 10 of 18 |
| Bore above smallest 33200-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33212U | 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 33212U model number is decoded
The NTN 2203E table prints 33212U in the medium-wide 33200 family: 60 mm bore, 110 mm cup OD, 38 mm T, with a grease limiting speed of 3,400 r/min and an oil-lubricated ceiling of 4,500 r/min. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 33212U by the metric ISO 355 number (ISO series abbreviation 3EE): 60 mm bore, 110 mm OD. The 25.0 mm radial section carries the roller complement across the 60–110 mm envelope; section and contact angle differ between NTN metric families even at the same bore, so 302/322/323 are not drop-in swaps. The fatigue load limit Pu printed for 33212U is 27.1 kN; in the adjusted-life equation that is the equivalent-load floor below which high reliability is expected even under contamination. When pairing 33212U 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
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
- rolling-mill auxiliary and pinion-stand shafts
- large conveyor and bucket-elevator pulleys
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- 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 60 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 1530 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The medium-wide 33200 family at 60 mm bore (110×38 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 4,500 r/min oil ceiling.
- Minimum load matters at high speed: an unloaded 33212U at a large fraction of 3,400 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- Grease packs must leave free volume in the 38 mm-wide set; over-greasing a paired bearing churning at the 4,500 r/min oil-band speed raises temperature and destroys the preload setting.
- The U/UTG/X/C/CA/D suffix variants of a base number share the bore but not the article: ordering 33212U by size alone can deliver the wrong contact-angle execution for a pinion position.
- The 179/223 kN ratings and 27.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33212U (ISO 355 3EE); 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 33212U?
33212U is a metric 4T tapered roller bearing to ISO 355: 60 mm bore, 110 mm outside diameter and 38 mm assembled width T (2.362 × 4.331 × 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 179 kN, C0 223 kN, Pu 27.1 kN, grease limiting speed 3,400 r/min, oil speed 4,500 r/min, mass about 1530 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33212U?
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 (33212U); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33212U designation encode the 60 mm bore and what is 3EE?
last two digits 12 are the ISO bore code, ×5 = 60 mm (codes 00–03 use the 10/12/15/17 exception table). The 110 mm OD and 38 mm assembled T follow the ISO 355 dimension-series plan. 3EE 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 33212U list two speeds, 3,400 and 4,500 r/min?
The lower figure, 3,400 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33212U at 4,500 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33212U mean?
Suffix reading on 33212U: 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.