C3138-KV bearing: complete specifications & equivalents
The C3138-KV is a ISO 15 radial bearing sized 190 x 320 x 104 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 190 mm |
| Outer diameter D | 320 mm |
| Width B | 104 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | none |
| Basic dynamic load rating C | 1700 kN |
| Basic static load rating C0 | 2550 kN |
| Fatigue load limit Pu | 224 kN |
| Limiting speed (mechanical) | 190 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 34000 g |
| Manufacturer designation | C 3138 KV |
| 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 & C3100-series range
| Bore d | 7.48 in |
|---|---|
| Outer diameter D | 12.598 in |
| Width B | 4.094 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 65 mm |
| Smallest bore in C3100-series | 100 mm |
| Largest outer diameter in C3100-series | 1580 mm |
| Width range across C3100-series | 52–462 mm |
| Bore position in C3100-series (smallest first) | 5 of 28 |
| Bore above smallest C3100-series size | 90 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C3138-V | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 190×320×104 mm ISO 15 envelope and equivalent catalogue C/C0; C 3138 V is the cylindrical-bore full-complement V execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ. |
| 23138 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 190×320×104 mm envelope as the SKF spherical roller bearing SKF 23138 CC/W33, but catalogue C/C0 differ (1700/2550 kN vs 1456/2080 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one. |
| 23138-CCK-W33 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 190×320×104 mm envelope as the SKF spherical roller bearing SKF 23138 CCK/W33, but catalogue C/C0 differ (1700/2550 kN vs 1456/2080 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one. |
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 C3138-KV model number is decoded
SKF lists C 3138 KV in the dimension series 31 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 3138 is the full-complement cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here KV. 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 190 mm seat. No thermal reference speed is listed for this full-complement execution; the mechanical limiting speed is 190 r/min. 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 heavy-loaded position — the 320 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
- edge loading and premature spalling when the CARB position is blocked from its designed axial float
- PA66 cage (TN9) softening when the sustained temperature passes the polymer limit
- rolling-contact fatigue spalling after the catalogue L10 life is exhausted
- oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips
Selection pitfalls — read before you substitute
- At 190 mm bore, shaft expansion is already measurable: calculate the required float inside the 104 mm wide bearing rather than assuming the free-end clearance is "enough" at operating temperature.
- Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3138 KV must float; the two are designed to be used as a pair.
- Never use C 3138 KV 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 1700/2550 kN ratings belong to this exact execution (C 3138 KV); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.
- Do not block the axial displacement in the drawing: housing covers, labyrinth rings and snap rings must leave the catalogue float (s) free, or the bearing silently becomes a poorly located fixed bearing.
- The 1700/2550 kN ratings and 34000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 864); 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 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 3138 KV have?
A C 3138 KV measures 190 mm bore × 320 mm outside diameter × 104 mm width (7.48 × 12.598 × 4.094 in). From SKF catalogue PUB BU/P1 17000: dynamic C 1700 kN, static C0 2550 kN, fatigue limit Pu 224 kN, limiting speed 190 r/min, no reference speed listed, mass about 34000 g.
What does C 3138 KV mean in SKF part numbering?
C marks CARB; 31 the dimension series; the size code gives 190 mm bore; KV is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, full-complement V execution (no cage)). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ.
Why is C 3138 KV 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.
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.