C3176-KMB bearing: complete specifications & equivalents
The C3176-KMB is a ISO 15 radial bearing sized 380 x 620 x 194 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 380 mm |
| Outer diameter D | 620 mm |
| Width B | 194 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 4400 kN |
| Basic static load rating C0 | 7200 kN |
| Fatigue load limit Pu | 520 kN |
| Reference speed (thermal) | 750 rpm |
| Limiting speed (mechanical) | 1000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 243000 g |
| Manufacturer designation | C 3176 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 | 14.961 in |
|---|---|
| Outer diameter D | 24.409 in |
| Width B | 7.638 in |
| ISO bore code | 76 |
| 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) | 15 of 28 |
| Bore above smallest C3100-series size | 280 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C3176-MB | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 380×620×194 mm ISO 15 envelope and equivalent catalogue C/C0; C 3176 MB is the cylindrical-bore MB inner-ring-guided brass-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ. |
| 23176 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (380×620×194 mm) SKF spherical roller bearing SKF 23176 CA/W33 with ratings within 10 % — not a drop-in substitute: SKF 23176 CA/W33 locates the shaft axially while the CARB bearing must float; the two are designed to run as a locating/non-locating pair. |
| 23176-CAK-W33 | SKF | full Dimensions and internal design equivalent — standard interchange. | Envelope-identical (380×620×194 mm) SKF spherical roller bearing SKF 23176 CAK/W33 with ratings within 10 % — not a drop-in substitute: SKF 23176 CAK/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 C3176-KMB model number is decoded
For long shafts that grow thermally, SKF supplies C 3176 KMB: the toroidal rollers allow the 380 mm inner ring to displace axially without induced thrust, while still accommodating shaft deflection like a spherical bearing. Reading the code: C marks the CARB toroidal family, the first two digits (31) identify the ISO dimension series and the last two (76) encode the 380 mm bore; suffixes describe bore and execution. The K suffix gives a 1:12 tapered 380 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 380×620×194 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 3176 KMB deliberately carries none. 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
- thermal preloading when a shaft is located at both ends and growth has nowhere to go
- brass cage pocket wear under marginal lubrication in the large-bore M/MB executions
- brinelling of washer raceways from impact or mounting force applied through the rolling elements
- oil starvation at the sliding contact zones of large spherical roller thrust bearings on forced-feed trips
Selection pitfalls — read before you substitute
- Above 200 mm bore these bearings weigh tens of kilograms (243 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 3176 KMB must float; the two are designed to be used as a pair.
- Never use C 3176 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.
- 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.
- Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 380 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- The 4400/7200 kN ratings and 243000 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
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 3176 KMB have?
A C 3176 KMB measures 380 mm bore × 620 mm outside diameter × 194 mm width (14.961 × 24.409 × 7.638 in). From SKF catalogue PUB BU/P1 17000: dynamic C 4400 kN, static C0 7200 kN, fatigue limit Pu 520 kN, reference speed 750 r/min, limiting speed 1,000 r/min, mass about 243000 g.
What does C 3176 KMB mean in SKF part numbering?
C marks CARB; 31 the dimension series; the size code gives 380 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.
Why is C 3176 KMB 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.