33011-NTN bearing: complete specifications & equivalents
The 33011-NTN is a ISO 355 radial bearing sized 55 x 90 x 27 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 | 90 mm |
| Width B | 27 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 102 kN |
| Basic static load rating C0 | 138 kN |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 654 g |
| Manufacturer designation | NTN 33011 |
| 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 | 2.165 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 1.063 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 17.5 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) | 7 of 24 |
| Bore above smallest 33000-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33011 | 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. |
| 33011-DF | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue. |
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 33011-NTN model number is decoded
33011 is a metric single-row tapered roller bearing in the NTN 4T programme: a pressed-steel cage guides profiled rollers between a separable cone and cup on the 55×90 mm ISO 355 envelope, with 27 mm overall assembled width T. NTN also quotes this bearing with its ISO 355 dimension-series abbreviation, 2CE, which is the maker-neutral cross-reference for the 55×90 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 102/138 kN (C/C0) the static rating is about 1.35× C, typical of tapered bearings proportioned for heavy combined duty. Selection: C 102 kN against C0 138 kN gives a C0/C ratio of 1.35 for the 55 mm bore, and the equivalent combined load must keep below the rating at the target L10 with the pair counted as one unit. Open 4T bearings need application seals; without them the grease at the cone rib of 33011 washes out and the rib/roller-end contact smears on the first wet or dusty shift.
Typical equipment & failure modes
Common applications
- machine-tool gearbox and headstock shafts
- axle final-drive and differential positions
- construction-equipment wheel and pivot hubs
- truck and bus wheel hubs in paired arrangements
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
- water-induced pitting when the open bearing is exposed to washdown without external seals
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 33011.
- The thin 27 mm section of 33011 is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 55 mm bore smears the roller ends against the rib.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 55 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- Never fit the 55 mm cone by hammering the 90 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Minimum load matters at high speed: an unloaded 33011 at a large fraction of 4,000 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 102/138 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33011 (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 33011?
33011 is a metric 4T tapered roller bearing to ISO 355: 55 mm bore, 90 mm outside diameter and 27 mm assembled width T (2.165 × 3.543 × 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 102 kN, C0 138 kN (2203E prints no Pu for this size), grease limiting speed 4,000 r/min, oil speed 5,400 r/min, mass about 654 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33011?
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 (33011); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33011 designation encode the 55 mm bore and what is 2CE?
last two digits 11 are the ISO bore code, ×5 = 55 mm (codes 00–03 use the 10/12/15/17 exception table). The 90 mm OD and 27 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 33011 list two speeds, 4,000 and 5,400 r/min?
The lower figure, 4,000 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33011 at 5,400 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33011 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.