33208-NTN bearing: complete specifications & equivalents
The 33208-NTN is a ISO 355 radial bearing sized 40 x 80 x 32 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 40 mm |
| Outer diameter D | 80 mm |
| Width B | 32 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 115 kN |
| Basic static load rating C0 | 132 kN |
| Limiting speed (mechanical) | 4900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 738 g |
| Manufacturer designation | NTN 33208 |
| 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 | 1.575 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 1.26 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 20 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) | 6 of 18 |
| Bore above smallest 33200-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33208 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 33208-NTN model number is decoded
33208 is the NTN 4T catalogue entry for a 40×80×32 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 33208 by the metric ISO 355 number (ISO series abbreviation 2DE): 40 mm bore, 80 mm OD. At 115 kN C the bearing offers about 2.9 kN of dynamic capacity per millimetre of the 40 mm bore — compare any substitution on this ratio and the 32 mm assembled T, not on bore alone. Imperial cross-check for the drawing: 40×80×32 mm is 1.575 × 3.15 × 1.26 in; ISO 355 makes the envelope interchangeable but C/C0, 115/132 kN, is NTN-specific. After mounting check the contact pattern with marking blue: a pattern biased to the large or small roller end means the 40 mm pair is misadjusted and the 32 mm T set will edge-load in service.
Typical equipment & failure modes
Common applications
- industrial gearbox and speed-reducer shafts
- bevel and helical pinion drives with high thrust component
- pump and compressor drive shafts carrying combined load
- machine-tool gearbox and headstock shafts
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- 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
- cage damage from a mounting blow delivered through the roller complement instead of the ring face
- brinell marks on cone and cup raceways from impact during handling or hammering during fitting
Selection pitfalls — read before you substitute
- Hub and pinion bearings of this 40 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 33208.
- The medium-wide 33200 family at 40 mm bore (80×32 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 6,600 r/min oil ceiling.
- Replacing one half of an adjusted pair without resetting end play negates the 32 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 40 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- Open 33208 units have no seals: a wheel-hub or gearbox application needs external sealing or the 4,900 r/min grease figure is meaningless once water reaches the cone rib.
- The 115/132 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33208 (ISO 355 2DE); 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 33208?
33208 is a metric 4T tapered roller bearing to ISO 355: 40 mm bore, 80 mm outside diameter and 32 mm assembled width T (1.575 × 3.15 × 1.26 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 115 kN, C0 132 kN (2203E prints no Pu for this size), grease limiting speed 4,900 r/min, oil speed 6,600 r/min, mass about 738 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33208?
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 (33208); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33208 designation encode the 40 mm bore and what is 2DE?
last two digits 08 are the ISO bore code, ×5 = 40 mm (codes 00–03 use the 10/12/15/17 exception table). The 80 mm OD and 32 mm assembled T follow the ISO 355 dimension-series plan. 2DE 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 33208 list two speeds, 4,900 and 6,600 r/min?
The lower figure, 4,900 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33208 at 6,600 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33208 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.