32309BR bearing: complete specifications & equivalents
The 32309BR is a ISO 355 radial bearing sized 45 x 100 x 38.25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 45 mm |
| Outer diameter D | 100 mm |
| Width B | 38.25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 166 kN |
| Basic static load rating C0 | 176 kN |
| Fatigue load limit Pu | 20 kN |
| Reference speed (thermal) | 5000 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1550 g |
| Manufacturer designation | SKF 32309 BR |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants |
| Last verified | 2026-09-29 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants) · extracted 2026-09-29
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & flanged-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 1.506 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in flanged-series | 35 mm |
| Largest outer diameter in flanged-series | 140 mm |
| Width range across flanged-series | 19–45.5 mm |
| Bore position in flanged-series (smallest first) | 3 of 5 |
| Bore above smallest flanged-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32309 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same d/D/T boundary as the plain single-row base bearing, but the flanged cup changes housing location — not a drop-in substitute where the flange is the axial register. |
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 32309BR model number is decoded
In SKF catalogue PUB BU/P1 17000, 32309BR appears as SKF 32309 BR: an open, single-row flanged tapered roller bearing for a 45 mm shaft, dimensioned 100 mm OD and 38.25 mm wide with the locating flange formed on the cup.The code SKF 32309 BR breaks down as the ISO 355 base bearing 32309 plus the flange suffix: same 45 mm bore, 100 mm OD and 38.25 mm width as the standard execution, with the cup extended into a locating flange. Substitution caution: a plain 32309 bearing cannot replace 32309BR where the housing has no shoulder on the flange side — the plain cup would lack axial location even though the 45×100×38.25 mm boundary matches. Speed planning uses two different ceilings: 5,000 r/min thermal reference and 6,700 r/min mechanical limiting speed. Assembly datum check: verify the 38.25 mm width against the drawing before clamping — the width is the assembled result and the quickest field check that the correct execution of 32309BR is on the shaft. Reversing-thrust shafts need a second tapered bearing facing 32309BR; the flange handles location on one side only, it does not make the bearing a double-direction unit.
Typical equipment & failure modes
Common applications
- pump and compressor shafts
- machine-tool spindles
- belt-driven fan and blower shafts
- belt-driven fan and blower shafts
Known failure patterns
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- fretting corrosion on a loose rotating shaft seat
- hard-particle indentation of the tapered raceway in unfiltered oil
Selection pitfalls — read before you substitute
- The flange does not change the one-direction thrust rule: 32309BR still needs a second tapered bearing facing it on reversing-thrust shafts, with the running clearance set at mounting.
- Do not press 32309BR home through the rollers: mounting force for the 45 mm bore seat goes through the cone face only, and the flanged cup is located by its flange, not by pressing the 100 mm OD.
- The flange face of 32309BR is the axial datum: protect it in handling — a nicked flange face tilts the cup in the housing and shows up as edge loading on the 100 mm OD raceway.
- The 166/176 kN ratings are SKF catalogue 17000 values for this execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification.
- Quote the full SKF 32309 BR designation when purchasing — base-number-only orders are ambiguous across executions and variants.
Frequently asked questions
What are the dimensions and catalogue data of 32309BR?
The SKF 32309 BR is a single-row tapered roller bearing with a flanged outer ring with 45 mm bore, 100 mm outer diameter and 38.25 mm overall width (1.772 × 3.937 × 1.506 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 166 kN, C0 176 kN, fatigue load limit Pu 20 kN, reference speed 5,000 r/min, limiting speed 6,700 r/min, mass about 1.55 kg.
What does the flanged outer ring on 32309BR do?
The cup of 32309BR carries an integral flange that locates the bearing axially against the housing face, so the housing needs no machined abutment shoulder on the flange side. It simplifies through-bored or cover-mounted housings; the running clearance is still set by cone-versus-cup position at mounting, exactly as for the plain 32309 bearing.
Is 32309BR interchangeable with the plain 32309 bearing?
The boundary dimensions 45×100×38.25 mm match the ISO 355 plan of the base bearing, but the flanged cup is a different order number. It is interchangeable only where the housing provides axial location by other means; where the flange is the locating feature, a plain cup cannot substitute.
Can a single 32309BR take axial load in both directions?
No — like any single-row tapered roller bearing it reacts thrust in one direction only, and under radial load its contact angle induces an axial force. Use two bearings as a matched pair (O or X arrangement) for reversing thrust.
What shaft and housing fits suit 32309BR?
For a rotating cone on the 45 mm shaft, use a k5 seat; the flanged cup is retained through the flange, so the 100 mm OD seat can be a loose-to-transition fit. Keep housing face runout square so the flange seats without tilting the cup.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants on 2026-09-29. Read our editorial & correction policy.