32009 bearing: complete specifications & equivalents
The 32009 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 |
|---|---|
| Bore diameter d | 45 mm |
| Outer diameter D | 75 mm |
| Width B | 20 mm |
| Seal / shield | open |
| Internal clearance | CN available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Operating temperature | -30 to +120 °C |
| Mass (geometry estimate) | 289 g |
| Standard | ISO 355 |
| Catalog version | iso355-geometry |
| Last verified | 2026-09-24 |
Source: ISO 15 boundary-dimensions standard · extracted 2026-09-24
Standard-interchange bearing: dimensions per ISO 15; CN clearance, P0 tolerance and a stamped-steel cage are catalogue defaults unless the supplier states otherwise, and mass is a geometry-derived estimate. Brand catalogue load ratings and limiting speeds for 32009 are being backfilled — use the inquiry form for certified values.
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 | 09 |
| Radial section height (D−d)/2 | 15 mm |
| Smallest bore in 32000-series | 20 mm |
| Largest outer diameter in 32000-series | 225 mm |
| Width range across 32000-series | 15–48 mm |
| Bore position in 32000-series (smallest first) | 6 of 23 |
| Bore above smallest 32000-series size | 25 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32009 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 32009 model number is decoded
In the 32000-series the last two digits of 32009 encode the bore: code 09 = 45 mm (code × 5 from 04 upward). The ISO 355 envelope is 75 mm outside diameter and 20 mm total assembly width T over the separable cone and cup — 1.772 × 2.953 × 0.787 in, with a 15.0 mm radial section height. Tapered rollers carry combined radial and single-direction axial load; bidirectional thrust needs an opposed pair (X face-to-face or O back-to-back) adjusted at fit-up. With a rotating cone on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore, EP lubrication and a defined end-play setting — verify against the load direction and magnitude.
Typical equipment & failure modes
Common applications
- industrial transmission shafts
- light-truck and van wheel hubs
- final-drive pinion and differential bearings
- commercial gearbox input/output shafts
- conveyor head and tail pulleys
Known failure patterns
- water and grit pitting in unsealed hubs where the cup-cone joint acts as a debris entry path
- false brinelling from vibration while the axle is stationary during transport
- fretting corrosion on a loose shaft seat when the cone is pressed to an interference that relaxes with wear
- cup creep and housing bore fretting when the outer ring is left without its specified press fit
- roller large-end smearing and scoring against the inner-ring guide rib from loss of the EP lubricant film
Selection pitfalls — read before you substitute
- On this 45 mm-bore 32009, thermal growth of the shaft closes up the adjusted clearance; set cold end play around 0.03–0.12 mm and recheck after the first hot run — a medium-series cone that was correct cold on the 45 mm seat can seize hot.
- The 320 narrow series at 45 mm bore keeps the OD down to 75 mm for space-limited hubs; its 20 mm width carries less load than a 30209, so do not substitute it into a 302 application without re-rating.
- The 20 mm-wide 32009 ring seats against a shaft and housing shoulder whose fillet must clear the bearing chamfer: keep the corner radius small enough that the 45 mm bore and 75 mm cup seat square — an undercut beats an oversized radius, which lifts the ring and edge-loads the 15.0 mm section.
- When mounting 32009 to a 45 mm shaft, warm the cone to 80–100 °C and slide it dry to the shoulder; cooling shrinks it into its interference, whereas hammering a cold cone through a 75 mm assembly dents the tapered raceway before first run.
- Inspect the removed 32009 cone and cup as a pair: pitting on the 75 mm cup with a clean cone usually means seal failure and water ingress, while rib scoring on the 45 mm cone points to wrong preload or lost EP film — the two faults need different corrections.
- Set running clearance (or preload) with the shim pack or adjusting nut at fit-up; a 45 mm-bore 32009 that is too tight overheats and scores the rib, one too loose develops end play and noise — follow the torque-and-untighten procedure.
- The sliding contact between roller large ends and the inner-ring rib needs extreme-pressure lubricant; use an EP gear oil or EP grease (GL-5 class in axles) rather than plain bearing grease or the rib will smear in the first heavy run.
Frequently asked questions
What are the dimensions of a 32009 tapered roller bearing?
A 32009 single-row metric tapered roller bearing per ISO 355 has a 45 mm bore, 75 mm outer diameter and 20 mm total assembly width (1.772 × 2.953 × 0.787 in), a 15.0 mm radial section and roughly 289 g geometry-based estimated mass; catalogue masses vary with roller and cage design.
How does the 32009 bore code work?
The last two digits of 32009 are bore code 09, giving 09 × 5 = 45 mm bore — the same convention as 6xx ball bearings, starting at code 04 (20 mm). The 75 mm OD and 20 mm width come from the ISO 355 diameter and width series, not the bore code alone.
What is the cone and cup of 32009?
Tapered roller bearings are separable: the cone is the inner ring with the tapered rollers and cage, the cup is the outer ring. 32009 denotes a matched cone-and-cup set. They are fitted separately — cone pressed on the shaft, cup in the housing — and adjusted against each other.
How is the preload or clearance of 32009 set?
At fit-up the 45 mm-bore cone is tightened against the cup while the hub is rotated, seated, then backed off to the specified end play — a typical starting range of 0.03–0.12 mm for a 45 mm bore — and locked with shims, a locknut or a spacer. Too tight overheats and seizes the rib; too loose causes skid, noise and early wear. Confirm the exact figure in the hub or axle-maker procedure.
Can 32009 take axial load in both directions?
A single 32009 takes thrust in one direction only — the roller large ends bear against the inner-ring rib under load. Bidirectional axial load requires an opposed pair: X (face-to-face) tolerates misalignment slightly better, O (back-to-back) gives a wider load centre and more moment stiffness.
Reviewed & verified by the MPN Base engineering desk against source catalog iso355-geometry on 2026-09-24. Read our editorial & correction policy.