C3168-M bearing: complete specifications & equivalents
The C3168-M is a ISO 15 radial bearing sized 340 x 580 x 190 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 340 mm |
| Outer diameter D | 580 mm |
| Width B | 190 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 4900 kN |
| Basic static load rating C0 | 7500 kN |
| Fatigue load limit Pu | 560 kN |
| Reference speed (thermal) | 850 rpm |
| Limiting speed (mechanical) | 1100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 205000 g |
| Manufacturer designation | C 3168 M |
| 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 | 13.386 in |
|---|---|
| Outer diameter D | 22.835 in |
| Width B | 7.48 in |
| ISO bore code | 68 |
| Radial section height (D−d)/2 | 120 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) | 13 of 28 |
| Bore above smallest C3100-series size | 240 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C3168-KM | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 340×580×190 mm ISO 15 envelope and equivalent catalogue C/C0; C 3168 KM is the 1:12 tapered-bore K M brass-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ. |
| 23168 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 340×580×190 mm envelope as the SKF spherical roller bearing SKF 23168 CC/W33, but catalogue C/C0 differ (4900/7500 kN vs 4445/6800 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one. |
| 23168-CCK-W33 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 340×580×190 mm envelope as the SKF spherical roller bearing SKF 23168 CCK/W33, but catalogue C/C0 differ (4900/7500 kN vs 4445/6800 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 C3168-M model number is decoded
C 3168 M belongs to the CARB family — compact aligning roller bearings: envelope 340×580×190 mm, radial rating 4900/7500 kN C/C0, and no axial-locating function by design. SKF builds the CARB order number from size plus execution: the bare number C 3168 is the brass-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here M. The cylindrical 340 mm bore mounts directly on a machined seat; the outer ring takes a loose housing fit so the bearing can float axially. The same size is listed in both bore executions, and the boundary dimensions 340×580×190 mm are identical — only the mounting method changes. Pairing rule: use the CARB bearing opposite one locating spherical or tapered bearing — never at both shaft ends — and check the locating bearing takes 100 % of the thrust, since C 3168 M deliberately carries none. 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 190 mm wide cavity does not fill itself.
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
- brass cage pocket wear under marginal lubrication in the large-bore M/MB executions
- hard-particle indentation where oil or grease filtration is inadequate
- abrasive paste forming as dust bypasses the housing seals into the open washer set
Selection pitfalls — read before you substitute
- Above 200 mm bore these bearings weigh tens of kilograms (205 kg here) — lifting gear and induction heating are mandatory, and a cocked ring scores the toroidal raceway before start-up.
- Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 340 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- Reference and limiting speeds are different limits: the 850 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.
- The quoted 4900/7500 kN ratings belong to this exact execution (C 3168 M); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.
- Never use C 3168 M 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 4900/7500 kN ratings and 205000 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
Is the C 3168 M 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.
Which dimensions does the C 3168 M have?
A C 3168 M measures 340 mm bore × 580 mm outside diameter × 190 mm width (13.386 × 22.835 × 7.48 in). From SKF catalogue PUB BU/P1 17000: dynamic C 4900 kN, static C0 7500 kN, fatigue limit Pu 560 kN, reference speed 850 r/min, limiting speed 1,100 r/min, mass about 205000 g.
What does C 3168 M mean in SKF part numbering?
C marks CARB; 31 the dimension series; the size code gives 340 mm bore; M is the execution (cylindrical bore for direct shaft fitting, machined brass M cage). 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.