32009X bearing: complete specifications & equivalents
The 32009X is a ISO 355 radial bearing sized 45 x 75 x 20 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 | 20 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 64 kN |
| Basic static load rating C0 | 76.5 kN |
| Limiting speed (mechanical) | 4800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 341 g |
| Manufacturer designation | NTN 32009X |
| 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 & 32000-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 2.953 in |
| Width B | 0.787 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 15 mm |
| Smallest bore in 32000-series | 20 mm |
| Largest outer diameter in 32000-series | 650 mm |
| Width range across 32000-series | 15–130 mm |
| Bore position in 32000-series (smallest first) | 9 of 43 |
| Bore above smallest 32000-series size | 25 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32009X-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 32009X model number is decoded
32009X is the NTN 4T catalogue entry for a 45×75×20 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. NTN also quotes this bearing with its ISO 355 dimension-series abbreviation, 3CC, which is the maker-neutral cross-reference for the 45×75 mm envelope; 4T is NTN's own tapered-roller brand mark on the parts. 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 32009X, since running clearance is set during assembly. Imperial cross-check for the drawing: 45×75×20 mm is 1.772 × 2.953 × 0.787 in; ISO 355 makes the envelope interchangeable but C/C0, 64/76.5 kN, is NTN-specific. When pairing 32009X with a second tapered bearing, keep the matched arrangement clean: a single stray grit particle between cup and housing changes preload faster than the adjustment range can correct.
Typical equipment & failure modes
Common applications
- truck and bus wheel hubs in paired arrangements
- industrial gearbox and speed-reducer shafts
- bevel and helical pinion drives with high thrust component
- pump and compressor drive shafts carrying combined load
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- fretting corrosion on a loose cone seat that creeps under rotating load
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 32009X.
- The thin 20 mm section of 32009X 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.
- Open 32009X units have no seals: a wheel-hub or gearbox application needs external sealing or the 4,800 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 45 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 45 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- The 64/76.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32009X (ISO 355 3CC); 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 32009X?
32009X is a metric 4T tapered roller bearing to ISO 355: 45 mm bore, 75 mm outside diameter and 20 mm assembled width T (1.772 × 2.953 × 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 64 kN, C0 76.5 kN (2203E prints no Pu for this size), grease limiting speed 4,800 r/min, oil speed 6,400 r/min, mass about 341 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32009X?
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 (32009X); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32009X designation encode the 45 mm bore and what is 3CC?
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 20 mm assembled T follow the ISO 355 dimension-series plan. 3CC 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 32009X 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 32009X 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 32009X mean?
Suffix reading on 32009X: X marks the execution built to the ISO boundary-dimension section (interchangeable envelope, NTN internal geometry); the suffix is part of the order number and the variants are not interchangeable articles.
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.