33009 bearing: complete specifications & equivalents
The 33009 is a ISO 355 radial bearing sized 45 x 75 x 24 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 45 mm |
| Outer diameter D | 75 mm |
| Width B | 24 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 73.5 kN |
| Basic static load rating C0 | 93.5 kN |
| Limiting speed (mechanical) | 4800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 405 g |
| Manufacturer designation | NTN 33009 |
| 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 | 1.772 in |
|---|---|
| Outer diameter D | 2.953 in |
| Width B | 0.945 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 15 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) | 5 of 24 |
| Bore above smallest 33000-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 33009 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the 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 33009 model number is decoded
33009 belongs to the NTN metric 4T tapered roller range (slim 33000 family); the open bearing leaves sealing to the application and is normally ordered and mounted as an adjustable matched pair. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 33009 by the metric ISO 355 number (ISO series abbreviation 2CE): 45 mm bore, 75 mm OD. The printed contact-angle geometry gives the slim 33000 family its characteristic load split — at 73.5/93.5 kN (C/C0) the static rating is about 1.27× C, typical of tapered bearings proportioned for heavy combined duty. Speed planning uses both catalogue columns: grease 4,800 r/min is the cage/rib mechanical ceiling for 33009, oil 6,400 r/min is available with circulating oil — a 1,600 r/min margin at this size. Mount the 45 mm-bore cone on the shaft first (induction heat, max 120 °C), fit the cup square in its housing, then set preload or end play; never drive the cup home through the rollers of 33009.
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
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- 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
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- false brinelling on a stationary paired set exposed to external vibration
Selection pitfalls — read before you substitute
- Hub and pinion bearings of this 45 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 33009.
- The thin 24 mm section of 33009 is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 45 mm bore smears the roller ends against the rib.
- Minimum load matters at high speed: an unloaded 33009 at a large fraction of 4,800 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- Never fit the 45 mm cone by hammering the 75 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 33009 at a large fraction of 4,800 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 73.5/93.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 33009 (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 33009?
33009 is a metric 4T tapered roller bearing to ISO 355: 45 mm bore, 75 mm outside diameter and 24 mm assembled width T (1.772 × 2.953 × 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 73.5 kN, C0 93.5 kN (2203E prints no Pu for this size), grease limiting speed 4,800 r/min, oil speed 6,400 r/min, mass about 405 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 33009?
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 (33009); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 33009 designation encode the 45 mm bore and what is 2CE?
last two digits 09 are the ISO bore code, ×5 = 45 mm (codes 00–03 use the 10/12/15/17 exception table). The 75 mm OD and 24 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 33009 list two speeds, 4,800 and 6,400 r/min?
The lower figure, 4,800 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 33009 at 6,400 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 33009 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.