C3148-K bearing: complete specifications & equivalents
The C3148-K is a ISO 15 radial bearing sized 240 x 400 x 128 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 240 mm |
| Outer diameter D | 400 mm |
| Width B | 128 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 2320 kN |
| Basic static load rating C0 | 3450 kN |
| Fatigue load limit Pu | 285 kN |
| Reference speed (thermal) | 1300 rpm |
| Limiting speed (mechanical) | 1700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 64000 g |
| Manufacturer designation | C 3148 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 & C3100-series range
| Bore d | 9.449 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 5.039 in |
| ISO bore code | 48 |
| Radial section height (D−d)/2 | 80 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) | 8 of 28 |
| Bore above smallest C3100-series size | 140 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C3148 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 240×400×128 mm ISO 15 envelope and equivalent catalogue C/C0; C 3148 is the cylindrical-bore steel-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ. |
| 23148 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (240×400×128 mm) SKF spherical roller bearing SKF 23148 CC/W33 with ratings within 10 % — not a drop-in substitute: SKF 23148 CC/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair. |
| 23148-CCK-W33 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (240×400×128 mm) SKF spherical roller bearing SKF 23148 CCK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23148 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 C3148-K model number is decoded
C 3148 K belongs to the CARB family — compact aligning roller bearings: envelope 240×400×128 mm, radial rating 2320/3450 kN C/C0, and no axial-locating function by design. The designation C 3148 K separates into C (CARB), 31 (dimension series), 48 (240 mm bore) and K (tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage); envelope 240×400×128 mm follows the ISO 15 plan. 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 240 mm seat. Selection arithmetic: C 2320 kN against C0 3450 kN gives a C0/C ratio of 1.49, and the 285 kN fatigue load limit Pu sets the contamination-adjusted life floor. Open executions accept relubrication — route it through the outer-ring groove on sizes that have one and purge stale grease at service intervals. Grease through the annular groove features where provided; on open executions feed lubricant past the long roller set at assembly, since the 128 mm wide cavity does not fill itself.
Typical equipment & failure modes
Common applications
- 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
- heavy industrial gearbox layshafts used as the non-locating position
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after sustained overload
- thermal preloading when a shaft is located at both ends and growth has nowhere to go
- PA66 cage (TN9) softening when the sustained temperature passes the polymer limit
- hard-particle indentation where oil or grease filtration is inadequate
- grease churning and overheating when a high-speed thrust position is over-packed
Selection pitfalls — read before you substitute
- Above 200 mm bore these bearings weigh tens of kilograms (64 kg here) — lifting gear and induction heating are mandatory, and a cocked ring scores the toroidal raceway before start-up.
- Never use C 3148 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.
- Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 240 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- 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.
- Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3148 K must float; the two are designed to be used as a pair.
- The 2320/3450 kN ratings and 64000 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 are the dimensions and ratings of the C 3148 K?
A C 3148 K measures 240 mm bore × 400 mm outside diameter × 128 mm width (9.449 × 15.748 × 5.039 in). From SKF catalogue PUB BU/P1 17000: dynamic C 2320 kN, static C0 3450 kN, fatigue limit Pu 285 kN, reference speed 1,300 r/min, limiting speed 1,700 r/min, mass about 64000 g.
Can a CARB bearing like C 3148 K locate the shaft axially?
No — that is the defining feature. C 3148 K deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust.
How is the C 3148 K designation read?
C = CARB toroidal family; 31 = dimension series; 48 = 240 mm bore (code 48 × 5); suffix K selects tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve.
What is the difference between V and TN9 CARB executions?
V is the full-complement execution with no cage — more rollers, higher C (2320 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 3148 K is the tapered 1:12 bore for adapter (H) sleeve mounting, pressed steel cage.
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.