C3224-K bearing: complete specifications & equivalents
The C3224-K is a ISO 15 radial bearing sized 120 x 215 x 76 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 120 mm |
| Outer diameter D | 215 mm |
| Width B | 76 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 750 kN |
| Basic static load rating C0 | 980 kN |
| Fatigue load limit Pu | 98 kN |
| Reference speed (thermal) | 2400 rpm |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12000 g |
| Manufacturer designation | C 3224 K |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings); 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 & C3200-series range
| Bore d | 4.724 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 2.992 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 47.5 mm |
| Smallest bore in C3200-series | 120 mm |
| Largest outer diameter in C3200-series | 830 mm |
| Width range across C3200-series | 76–296 mm |
| Bore position in C3200-series (smallest first) | 1 of 4 |
| Bore above smallest C3200-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C3224 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 120×215×76 mm ISO 15 envelope and equivalent catalogue C/C0; C 3224 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ. |
| 23224 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (120×215×76 mm) SKF spherical roller bearing SKF 23224 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23224 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair. |
| 23224-CCK-W33 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (120×215×76 mm) SKF spherical roller bearing SKF 23224 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23224 CCK/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair. |
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 C3224-K model number is decoded
C 3224 K belongs to the CARB family — compact aligning roller bearings: envelope 120×215×76 mm, radial rating 750/980 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (32) identify the ISO dimension series and the last two (24) encode the 120 mm bore; suffixes describe bore and execution. The K suffix gives a 1:12 tapered 120 mm bore, mounted on an adapter (H) sleeve so the bearing can be driven up to the specified clearance. The same size is listed in both bore executions, and the boundary dimensions 120×215×76 mm are identical — only the mounting method changes. Speed planning separates the 2,400 r/min thermal reference from the 3,200 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the steel-caged executions run faster and cooler at light load. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 215 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.
Typical equipment & failure modes
Common applications
- winder and reel drums in paper and steel strip plants
- paper machine drying cylinders and calender rolls with long, thermally expanding shafts
- continuous-caster guide rolls and slab-caster segments under heat growth
- vibrating screen exciters fitted with the VE240 tolerance execution
Known failure patterns
- roller-end and flange smearing after lubricant starvation at the long roller contacts
- thermal preloading when a shaft is located at both ends and growth has nowhere to go
- brass cage pocket wear under marginal lubrication in the large-bore M/MB executions
- rolling-contact fatigue spalling after the catalogue L10 life is exhausted
- grease churning and overheating when a high-speed thrust position is over-packed
Selection pitfalls — read before you substitute
- At 120 mm bore, shaft expansion is already measurable: calculate the required float inside the 76 mm wide bearing rather than assuming the free-end clearance is "enough" at operating temperature.
- Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 120 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- Reference and limiting speeds are different limits: the 2,400 r/min reference speed is the thermal criterion under load, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.
- Never use C 3224 K as the locating bearing: it carries no axial load by design — the arrangement needs a separate locating spherical, tapered or angular bearing facing the thrust.
- The quoted 750/980 kN ratings belong to this exact execution (C 3224 K); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.
- The 750/980 kN ratings and 12000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 862); mounting data — axial displacement (s) and seating details — appears in the running text because the structured record carries the boundary envelope only.
Frequently asked questions
What does C 3224 K mean in SKF part numbering?
C marks CARB; 32 the dimension series; the size code gives 120 mm bore; K is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ.
Why is C 3224 K used opposite a spherical roller bearing?
The spherical bearing locates the shaft and takes thrust; the CARB bearing at the other end self-aligns but floats, absorbing thermal expansion without inducing axial load. The pair is standard on paper machine drying cylinders and long caster rolls.
Is the C 3224 K sealed?
No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size.
What fails first on a misapplied CARB bearing?
Blocking the designed axial float — clamping the free end or locating both shaft ends — turns thermal growth into edge loading and spalls the toroidal raceways. Cage damage and ordinary fatigue follow overload or dry running.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 10.1 CARB toroidal roller bearings on 2026-09-27. Read our editorial & correction policy.