33111-NTN bearing: complete specifications & equivalents
The 33111-NTN is a ISO 355 radial bearing sized 55 x 95 x 30 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 | 95 mm |
| Width B | 30 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 | 155 kN |
| Limiting speed (mechanical) | 3900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 858 g |
| Manufacturer designation | NTN 33111 |
| 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 & 33100-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 3.74 in |
| Width B | 1.181 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in 33100-series | 40 mm |
| Largest outer diameter in 33100-series | 200 mm |
| Width range across 33100-series | 26–62 mm |
| Bore position in 33100-series (smallest first) | 4 of 13 |
| Bore above smallest 33100-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33111 | 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 33111-NTN model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the NTN order number 33111 denotes the light-wide 33100 family of metric tapered roller bearings, 55 mm bore, 95 mm outside diameter and 30 mm assembled width T (2.165 × 3.74 × 1.181 in) to the ISO 355 boundary plan. The last two digits 11 are the ISO bore code, ×5 = 55 mm (codes 00–03 use the 10/12/15/17 exception table) under the ISO 355 numbering; the 30 mm value printed here is T, the width of the fully assembled cone-plus-cup set, not the inner-ring width alone. 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 33111, since running clearance is set during assembly. Speed planning uses both catalogue columns: grease 3,900 r/min is the cage/rib mechanical ceiling for 33111, oil 5,200 r/min is available with circulating oil — a 1,300 r/min margin at this size. Fillet radii must clear the ring chamfers of the 95 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
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- edge loading when shaft deflection exceeds the few arc-minutes of misalignment the adjusted pair allows
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 33111.
- The light-wide 33100 family at 55 mm bore (95×30 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 5,200 r/min oil ceiling.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 55 mm shoulder geometry, because retrofitting flips the cups.
- Open 33111 units have no seals: a wheel-hub or gearbox application needs external sealing or the 3,900 r/min grease figure is meaningless once water reaches the cone 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.
- The 123/155 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33111 (ISO 355 3CE); 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 33111?
33111 is a metric 4T tapered roller bearing to ISO 355: 55 mm bore, 95 mm outside diameter and 30 mm assembled width T (2.165 × 3.74 × 1.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 123 kN, C0 155 kN (2203E prints no Pu for this size), grease limiting speed 3,900 r/min, oil speed 5,200 r/min, mass about 858 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33111?
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 (33111); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33111 designation encode the 55 mm bore and what is 3CE?
last two digits 11 are the ISO bore code, ×5 = 55 mm (codes 00–03 use the 10/12/15/17 exception table). The 95 mm OD and 30 mm assembled T follow the ISO 355 dimension-series plan. 3CE 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 33111 list two speeds, 3,900 and 5,200 r/min?
The lower figure, 3,900 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33111 at 5,200 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33111 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.