C3188-KMB bearing: complete specifications & equivalents
The C3188-KMB is a ISO 15 radial bearing sized 440 x 720 x 226 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 440 mm |
| Outer diameter D | 720 mm |
| Width B | 226 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 6700 kN |
| Basic static load rating C0 | 11400 kN |
| Fatigue load limit Pu | 780 kN |
| Reference speed (thermal) | 630 rpm |
| Limiting speed (mechanical) | 850 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 385000 g |
| Manufacturer designation | C 3188 KMB |
| 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 | 17.323 in |
|---|---|
| Outer diameter D | 28.346 in |
| Width B | 8.898 in |
| ISO bore code | 88 |
| Radial section height (D−d)/2 | 140 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) | 18 of 28 |
| Bore above smallest C3100-series size | 340 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C3188-MB | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 440×720×226 mm ISO 15 envelope and equivalent catalogue C/C0; C 3188 MB is the cylindrical-bore MB inner-ring-guided brass-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ. |
| 23188 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 440×720×226 mm envelope as the SKF spherical roller bearing SKF 23188 CA/W33, but catalogue C/C0 differ (6700/11400 kN vs 6215/10000 kN) — and the functions differ: spherical locates axially, CARB floats. Pair them; never swap one-for-one. |
| 23188-CAK-W33 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 440×720×226 mm envelope as the SKF spherical roller bearing SKF 23188 CAK/W33, but catalogue C/C0 differ (6700/11400 kN vs 6215/10000 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 C3188-KMB model number is decoded
C 3188 KMB is the dimension series 31 CARB toroidal roller bearings member of the CARB range: 440 mm bore, 720 mm OD, 226 mm width, with the asymmetrical-looking toroidal roller set that defines the CARB principle. SKF builds the CARB order number from size plus execution: the bare number C 3188 is the brass-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here KMB. The K suffix gives a 1:12 tapered 440 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 440×720×226 mm are identical — only the mounting method changes. The 385000 g mass over the 440×720×226 mm envelope yields about 15.23 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the heavy-loaded position — the 720 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
- brass cage pocket wear under marginal lubrication in the large-bore M/MB executions
- electrical erosion of raceways on VFD-driven shafts without grounding or insulation
- 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 (385 kg here) — lifting gear and induction heating are mandatory, and a cocked ring scores the toroidal raceway before start-up.
- Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 3188 KMB must float; the two are designed to be used as a pair.
- Never use C 3188 KMB 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 6700/11400 kN ratings belong to this exact execution (C 3188 KMB); 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 6700/11400 kN ratings and 385000 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 866); 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 3188 KMB 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 3188 KMB have?
A C 3188 KMB measures 440 mm bore × 720 mm outside diameter × 226 mm width (17.323 × 28.346 × 8.898 in). From SKF catalogue PUB BU/P1 17000: dynamic C 6700 kN, static C0 11400 kN, fatigue limit Pu 780 kN, reference speed 630 r/min, limiting speed 850 r/min, mass about 385000 g.
What does C 3188 KMB mean in SKF part numbering?
C marks CARB; 31 the dimension series; the size code gives 440 mm bore; KMB is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, machined inner-ring-guided brass cage (MB)). 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.