32311BR bearing: complete specifications & equivalents
The 32311BR is a ISO 355 radial bearing sized 55 x 120 x 45.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 55 mm |
| Outer diameter D | 120 mm |
| Width B | 45.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 233 kN |
| Basic static load rating C0 | 260 kN |
| Fatigue load limit Pu | 30 kN |
| Reference speed (thermal) | 4300 rpm |
| Limiting speed (mechanical) | 5600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2550 g |
| Manufacturer designation | SKF 32311 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 | 2.165 in |
|---|---|
| Outer diameter D | 4.724 in |
| Width B | 1.791 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 32.5 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) | 4 of 5 |
| Bore above smallest flanged-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32311 | 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 32311BR model number is decoded
Ordering number SKF 32311 BR in SKF catalogue PUB BU/P1 17000 denotes a flanged single-row tapered roller bearing for a 55 mm shaft: combined radial and one-direction axial load, separable mounting, and a cup flange that simplifies housing design.The code SKF 32311 BR breaks down as the ISO 355 base bearing 32311 plus the flange suffix: same 55 mm bore, 120 mm OD and 45.5 mm width as the standard execution, with the cup extended into a locating flange. Substitution caution: a plain 32311 bearing cannot replace 32311BR where the housing has no shoulder on the flange side — the plain cup would lack axial location even though the 55×120×45.5 mm boundary matches. Speed planning uses two different ceilings: 4,300 r/min thermal reference and 5,600 r/min mechanical limiting speed. Dimensional interchange map: within its boundary plan the 55×120×45.5 mm envelope of 32311BR is fixed, so shoulder, spacer and seal drawings can be dimensioned straight from the catalogue table. Fit selection follows the rotating ring: a rotating cone on the 55 mm shaft takes a k5 seat; the flanged cup is clamped through its flange and does not need a tight housing fit on the 120 mm OD.
Typical equipment & failure modes
Common applications
- axle-boxes in material-handling equipment
- automotive and light-truck wheel hubs
- industrial gearbox shafts and reducers
- differential and pinion drives
Known failure patterns
- false brinelling on idle paired sets exposed to machine vibration
- roller large-end smearing against the cone rib after EP lubricant film failure
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- brinelling from pressing the cone or cup home through the rollers
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- The flange does not change the one-direction thrust rule: 32311BR still needs a second tapered bearing facing it on reversing-thrust shafts, with the running clearance set at mounting.
- The flange does not change the one-direction thrust rule: 32311BR still needs a second tapered bearing facing it on reversing-thrust shafts, with the running clearance set at mounting.
- The flange face of 32311BR 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 120 mm OD raceway.
- The 233/260 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 32311 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 32311BR?
The SKF 32311 BR is a single-row tapered roller bearing with a flanged outer ring with 55 mm bore, 120 mm outer diameter and 45.5 mm overall width (2.165 × 4.724 × 1.791 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 233 kN, C0 260 kN, fatigue load limit Pu 30 kN, reference speed 4,300 r/min, limiting speed 5,600 r/min, mass about 2.55 kg.
What does the flanged outer ring on 32311BR do?
The cup of 32311BR 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 32311 bearing.
Is 32311BR interchangeable with the plain 32311 bearing?
The boundary dimensions 55×120×45.5 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 32311BR 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 32311BR?
For a rotating cone on the 55 mm shaft, use a k5 seat; the flanged cup is retained through the flange, so the 120 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.