C4128-2CS5V-GEM9 bearing: complete specifications & equivalents
The C4128-2CS5V-GEM9 is a ISO 15 radial bearing sized 140 x 225 x 85 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 140 mm |
| Outer diameter D | 225 mm |
| Width B | 85 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 780 kN |
| Basic static load rating C0 | 1200 kN |
| Fatigue load limit Pu | 116 kN |
| Limiting speed (mechanical) | 63 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12500 g |
| Manufacturer designation | C 4128-2CS5V/GEM9 |
| 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 & C4100-series range
| Bore d | 5.512 in |
|---|---|
| Outer diameter D | 8.858 in |
| Width B | 3.346 in |
| ISO bore code | 28 |
| Radial section height (D−d)/2 | 42.5 mm |
| Smallest bore in C4100-series | 100 mm |
| Largest outer diameter in C4100-series | 1090 mm |
| Width range across C4100-series | 65–412 mm |
| Bore position in C4100-series (smallest first) | 5 of 14 |
| Bore above smallest C4100-series size | 40 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C4128-V-VE240 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 140×225×85 mm ISO 15 envelope and equivalent catalogue C/C0; C 4128 V/VE240 is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ. |
| 24128 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (140×225×85 mm) SKF spherical roller bearing SKF 24128 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 24128 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair. |
| 24128-CCK30-W33 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (140×225×85 mm) SKF spherical roller bearing SKF 24128 CCK30/W33 with ratings within 10 % — not a drop-in substitute: SKF 24128 CCK30/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 C4128-2CS5V-GEM9 model number is decoded
SKF lists C 4128-2CS5V/GEM9 in the dimension series 41 CARB toroidal roller bearings: the toroidal roller profile both follows tolerates angular misalignment and lets the inner ring slide axially inside the outer ring, giving free axial displacement at the non-locating position. SKF builds the CARB order number from size plus execution: the bare number C 4128 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here 2CS5V/GEM9. CARB bearings locate neither radially nor axially: the inner ring can walk axially inside the outer ring over the catalogue-listed axial-displacement range (s), so shaft thermal growth disappears as thrust rather than preloading the 140 mm seat. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 85 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. After fitting, confirm the inner ring can be pushed axially by hand through the catalogue displacement range; a ring that will not slide means the position is locked and will preload in service.
Typical equipment & failure modes
Common applications
- 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
- long fan and kiln main shafts where the free end must float without thrust load
Known failure patterns
- roller-end and flange smearing after lubricant starvation at the long roller contacts
- roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders
- PA66 cage (TN9) softening when the sustained temperature passes the polymer limit
- condensation pitting in machines that run intermittently in humid environments
- oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips
Selection pitfalls — read before you substitute
- At 140 mm bore, shaft expansion is already measurable: calculate the required float inside the 85 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 140 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- Reference and limiting speeds are different limits: the catalogue lists no thermal reference speed for this full-complement/sealed execution, the limiting value is the mechanical ceiling; observe the reference under load unless the arrangement calculation says otherwise.
- The quoted 780/1200 kN ratings belong to this exact execution (C 4128-2CS5V/GEM9); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.
- Never use C 4128-2CS5V/GEM9 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 780/1200 kN ratings and 12500 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
Is the C 4128-2CS5V/GEM9 sealed?
Yes — this is a sealed full-complement execution (2CS5V contact seals with annular groove), greased at the factory; the catalogue lists no reference speed and the limiting speed is 63 r/min.
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.
Which dimensions does the C 4128-2CS5V/GEM9 have?
A C 4128-2CS5V/GEM9 measures 140 mm bore × 225 mm outside diameter × 85 mm width (5.512 × 8.858 × 3.346 in). From SKF catalogue PUB BU/P1 17000: dynamic C 780 kN, static C0 1200 kN, fatigue limit Pu 116 kN, limiting speed 63 r/min, no reference speed listed, mass about 12500 g.
What does C 4128-2CS5V/GEM9 mean in SKF part numbering?
C marks CARB; 41 the dimension series; the size code gives 140 mm bore; 2CS5V/GEM9 is the execution (cylindrical bore for direct shaft fitting, 2CS5V/GEM9 sealed full-complement execution with annular groove). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ.
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.