C30-630-M bearing: complete specifications & equivalents
The C30-630-M 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 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 & 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-KM | 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 KM is the 1:12 tapered-bore K 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-M model number is decoded
C 30/630 M is a CARB toroidal roller bearing to ISO 15: a single row of long, symmetrical barrel-shaped rollers between guide flanges, sized 630×920×212 mm, as listed in SKF catalogue PUB BU/P1 17000 ch. 10.1. The designation C 30/630 M separates into C (CARB), 30 (dimension series), 630 mm (slash-size) (630 mm bore — bore 630 mm is written directly after the slash) and M (cylindrical bore for direct shaft fitting, machined brass M cage); envelope 630×920×212 mm follows the ISO 15 plan. 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 630 mm seat. 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 30/630 M 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
- 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
- heavy industrial gearbox layshafts used as the non-locating position
Known failure patterns
- raceway spalling once the catalogue L10 life is exceeded or after sustained overload
- 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
- condensation pitting in machines that run intermittently in humid environments
- abrasive paste forming as dust bypasses the housing seals into the open washer set
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.
- Never use C 30/630 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.
- 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.
- 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.
- Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 30/630 M must float; the two are designed to be used as a pair.
- 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
Can a CARB bearing like C 30/630 M locate the shaft axially?
No — that is the defining feature. C 30/630 M deliberately allows the inner ring to float axially inside the outer ring while the toroidal rollers self-align. It must be paired with a separate locating bearing (spherical, tapered or angular contact) that takes 100 % of the thrust.
How is the C 30/630 M designation read?
C = CARB toroidal family; 30 = dimension series; 630 mm (slash-size) = 630 mm bore (the bore is written directly after the slash (no bore code)); suffix M selects cylindrical bore for direct shaft fitting, machined brass M cage. K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve.
What is the difference between V and TN9 CARB executions?
V is the full-complement execution with no cage — more rollers, higher C (6800 kN here) but a lower speed ceiling and no thermal reference speed. TN9 is the glass-fibre PA66 caged execution, faster and quieter at somewhat lower load. C 30/630 M is the cylindrical bore for direct shaft fitting, machined brass M cage.
How is C 30/630 M mounted?
Slide or heat (max 120 °C) the bearing onto the 630 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 212 mm roller set.
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.