C30-500-M bearing: complete specifications & equivalents
The C30-500-M is a ISO 15 radial bearing sized 500 x 720 x 167 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 500 mm |
| Outer diameter D | 720 mm |
| Width B | 167 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 4250 kN |
| Basic static load rating C0 | 8300 kN |
| Fatigue load limit Pu | 560 kN |
| Reference speed (thermal) | 630 rpm |
| Limiting speed (mechanical) | 900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 225000 g |
| Manufacturer designation | C 30/500 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 | 19.685 in |
|---|---|
| Outer diameter D | 28.346 in |
| Width B | 6.575 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 110 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) | 21 of 33 |
| Bore above smallest C3000-series size | 380 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the C30-500-M model number is decoded
The CARB bearing C 30/500 M combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 500 mm bore, 720 mm outside diameter, 167 mm wide unit rated 4250 kN dynamic. SKF builds the CARB order number from size plus execution: the bare number C 30/500 is the brass-caged cylindrical-bore bearing, K (or K30) makes the bore tapered for sleeve mounting, and the cage/seal letters follow — here M. The M suffix is a one-piece machined brass cage centred on the rollers, supplied for the 500 mm and larger sizes needing robust guidance under heavy load. Float capacity is a selection criterion: the catalogue lists the permissible axial displacement (s) for the 167 mm wide set; size the free-end housing so thermal growth stays within it, not just inside the overall width. Mounting: slide the bearing onto the 500 mm seat or heat it (max 120 °C) and seat it square; never press through the 167 mm roller set, and leave the free-end housing shoulder clear so axial float is unrestricted.
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
- roller skew and cage damage after the bearing is clamped solid between shaft and housing shoulders
- PA66 cage (TN9) softening when the sustained temperature passes the polymer limit
- rolling-contact fatigue spalling after the catalogue L10 life is exhausted
- 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 (225 kg here) — lifting gear and induction heating are mandatory, and a cocked ring scores the toroidal raceway before start-up.
- The quoted 4250/8300 kN ratings belong to this exact execution (C 30/500 M); 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.
- Envelope-identical spherical roller bearings (same ISO 15 d×D×B) are not drop-in equivalents — they locate the shaft axially, while C 30/500 M must float; the two are designed to be used as a pair.
- Never use C 30/500 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.
- The 4250/8300 kN ratings and 225000 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
Which dimensions does the C 30/500 M have?
A C 30/500 M measures 500 mm bore × 720 mm outside diameter × 167 mm width (19.685 × 28.346 × 6.575 in). From SKF catalogue PUB BU/P1 17000: dynamic C 4250 kN, static C0 8300 kN, fatigue limit Pu 560 kN, reference speed 630 r/min, limiting speed 900 r/min, mass about 225000 g.
What does C 30/500 M mean in SKF part numbering?
C marks CARB; 30 the dimension series; the size code gives 500 mm bore; M is the execution (cylindrical bore for direct shaft fitting, machined brass M cage). The envelope follows ISO 15 and matches spherical roller bearing outlines, but the functions differ.
Why is C 30/500 M 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 30/500 M sealed?
No, it is an open execution relying on the housing seals; relubrication follows the groove/hole features of the size.
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.