C30-630-KM bearing: complete specifications & equivalents
The C30-630-KM is a ISO 15 radial bearing sized 630 x 920 x 212 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 630 mm |
| Outer diameter D | 920 mm |
| Width B | 212 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 6800 kN |
| Basic static load rating C0 | 12900 kN |
| Fatigue load limit Pu | 815 kN |
| Reference speed (thermal) | 480 rpm |
| Limiting speed (mechanical) | 670 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 470000 g |
| Manufacturer designation | C 30/630 KM |
| 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 & C3000-series range
| Bore d | 24.803 in |
|---|---|
| Outer diameter D | 36.22 in |
| Width B | 8.346 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 145 mm |
| Smallest bore in C3000-series | 120 mm |
| Largest outer diameter in C3000-series | 1420 mm |
| Width range across C3000-series | 46–308 mm |
| Bore position in C3000-series (smallest first) | 25 of 33 |
| Bore above smallest C3000-series size | 510 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C30-630-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 630×920×212 mm ISO 15 envelope and equivalent catalogue C/C0; C 30/630 M is the cylindrical-bore M brass-caged execution of this size — boundary dimensions interchangeable, only mounting and cage execution differ. |
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 C30-630-KM model number is decoded
C 30/630 KM belongs to the CARB family — compact aligning roller bearings: envelope 630×920×212 mm, radial rating 6800/12900 kN C/C0, and no axial-locating function by design. Reading the code: C marks the CARB toroidal family, the first two digits (30) identify the ISO dimension series and the last two (630 mm (slash-size)) encode the 630 mm bore; suffixes describe bore and execution. The K suffix gives a 1:12 tapered 630 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 630×920×212 mm are identical — only the mounting method changes. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 212 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. 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 212 mm wide cavity does not fill itself.
Typical equipment & failure modes
Common applications
- heavy industrial gearbox layshafts used as the non-locating position
- 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
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
- condensation pitting in machines that run intermittently in humid environments
- grease churning and overheating when a high-speed thrust position is over-packed
Selection pitfalls — read before you substitute
- At 630 mm bore the 470 kg mass and 212 mm width make seating geometry dominant: sphered-washer seats and oil flow must be verified in place, not just on the drawing.
- Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 630 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- Reference and limiting speeds are different limits: the 480 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.
- Never use C 30/630 KM 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 6800/12900 kN ratings belong to this exact execution (C 30/630 KM); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.
- The 6800/12900 kN ratings and 470000 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
Why is C 30/630 KM 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.
Is the C 30/630 KM 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 30/630 KM have?
A C 30/630 KM measures 630 mm bore × 920 mm outside diameter × 212 mm width (24.803 × 36.22 × 8.346 in). From SKF catalogue PUB BU/P1 17000: dynamic C 6800 kN, static C0 12900 kN, fatigue limit Pu 815 kN, reference speed 480 r/min, limiting speed 670 r/min, mass about 470000 g.
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.