33211-NTN bearing: complete specifications & equivalents
The 33211-NTN is a ISO 355 radial bearing sized 55 x 100 x 35 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 55 mm |
| Outer diameter D | 100 mm |
| Width B | 35 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 153 kN |
| Basic static load rating C0 | 188 kN |
| Limiting speed (mechanical) | 3600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1170 g |
| Manufacturer designation | NTN 33211 |
| 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 | 2.165 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 1.378 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 22.5 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) | 9 of 18 |
| Bore above smallest 33200-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33211 | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per 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 33211-NTN model number is decoded
NTN supplies this 55 mm bore tapered roller position as 33211: one cone assembly, one cup, line-contact rollers and a steel cage, rated 153 kN basic dynamic and 188 kN static on the medium-wide 33200 family. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 33211 by the metric ISO 355 number (ISO series abbreviation 3DE): 55 mm bore, 100 mm OD. The printed contact-angle geometry gives the medium-wide 33200 family its characteristic load split — at 153/188 kN (C/C0) the static rating is about 1.23× C, typical of tapered bearings proportioned for heavy combined duty. Catalogue mass of the 33211 set is 1170 g (0.046 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 100 mm cup and 55 mm cone; use undercut shoulders so the rings seat fully rather than bridging on a shaft radius.
Typical equipment & failure modes
Common applications
- pump and compressor drive shafts carrying combined load
- machine-tool gearbox and headstock shafts
- axle final-drive and differential positions
- construction-equipment wheel and pivot hubs
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 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
- Hub and pinion bearings of this 55 mm bore class are commonly adjusted in pairs; verify end play against the axle drawing and re-torque after bedding-in rather than trusting the initial preload on 33211.
- The medium-wide 33200 family at 55 mm bore (100×35 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 4,900 r/min oil ceiling.
- Never fit the 55 mm cone by hammering the 100 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- ISO 355 makes the 55×100 mm envelope interchangeable but not the ratings: NTN prints 153/188 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- Minimum load matters at high speed: an unloaded 33211 at a large fraction of 3,600 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 153/188 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33211 (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 33211?
33211 is a metric 4T tapered roller bearing to ISO 355: 55 mm bore, 100 mm outside diameter and 35 mm assembled width T (2.165 × 3.937 × 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 153 kN, C0 188 kN (2203E prints no Pu for this size), grease limiting speed 3,600 r/min, oil speed 4,900 r/min, mass about 1170 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33211?
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 (33211); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33211 designation encode the 55 mm bore and what is 3DE?
last two digits 11 are the ISO bore code, ×5 = 55 mm (codes 00–03 use the 10/12/15/17 exception table). The 100 mm OD and 35 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 33211 list two speeds, 3,600 and 4,900 r/min?
The lower figure, 3,600 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33211 at 4,900 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33211 mean?
It is the basic open 4T execution — steel cage, adjusted mounting, no seal or feature suffix. NTN uses U for the uprated design, UTG for ULTAGE large-bearing specs, X for the ISO boundary section, and C/CA/D/A for contact-angle or internal-design variants; all are separate order numbers.
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.