C30-530-KM bearing: complete specifications & equivalents
The C30-530-KM is a ISO 15 radial bearing sized 530 x 780 x 185 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 530 mm |
| Outer diameter D | 780 mm |
| Width B | 185 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 5100 kN |
| Basic static load rating C0 | 9500 kN |
| Fatigue load limit Pu | 630 kN |
| Reference speed (thermal) | 600 rpm |
| Limiting speed (mechanical) | 800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 300000 g |
| Manufacturer designation | C 30/530 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 | 20.866 in |
|---|---|
| Outer diameter D | 30.709 in |
| Width B | 7.283 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 125 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) | 22 of 33 |
| Bore above smallest C3000-series size | 410 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C30-530-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 530×780×185 mm ISO 15 envelope and equivalent catalogue C/C0; C 30/530 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 C30-530-KM model number is decoded
C 30/530 KM is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 530×780×185 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. Reading the code: C marks the CARB toroidal family, the first two digits (30) identify the ISO dimension series and the last two (530 mm (slash-size)) encode the 530 mm bore; suffixes describe bore and execution. 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 530 mm seat. Selection arithmetic: C 5100 kN against C0 9500 kN gives a C0/C ratio of 1.86, and the 630 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 185 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
- 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
- At 530 mm bore the 300 kg mass and 185 mm width make seating geometry dominant: sphered-washer seats and oil flow must be verified in place, not just on the drawing.
- Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 30/530 KM must float; the two are designed to be used as a pair.
- Never use C 30/530 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.
- 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 530 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- The 5100/9500 kN ratings and 300000 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 30/530 KM have?
A C 30/530 KM measures 530 mm bore × 780 mm outside diameter × 185 mm width (20.866 × 30.709 × 7.283 in). From SKF catalogue PUB BU/P1 17000: dynamic C 5100 kN, static C0 9500 kN, fatigue limit Pu 630 kN, reference speed 600 r/min, limiting speed 800 r/min, mass about 300000 g.
What does C 30/530 KM mean in SKF part numbering?
C marks CARB; 30 the dimension series; the size code gives 530 mm bore; KM is the execution (tapered 1:12 bore for adapter (H) sleeve mounting, machined brass M cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ.
Why is C 30/530 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.
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.