C39-500-M bearing: complete specifications & equivalents
The C39-500-M is a ISO 15 radial bearing sized 500 x 670 x 128 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 | 670 mm |
| Width B | 128 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 3150 kN |
| Basic static load rating C0 | 6300 kN |
| Fatigue load limit Pu | 430 kN |
| Reference speed (thermal) | 700 rpm |
| Limiting speed (mechanical) | 950 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 125000 g |
| Manufacturer designation | C 39/500 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 & C3900-series range
| Bore d | 19.685 in |
|---|---|
| Outer diameter D | 26.378 in |
| Width B | 5.039 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 85 mm |
| Smallest bore in C3900-series | 360 mm |
| Largest outer diameter in C3900-series | 2180 mm |
| Width range across C3900-series | 90–355 mm |
| Bore position in C3900-series (smallest first) | 5 of 15 |
| Bore above smallest C3900-series size | 140 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C39-500-KM | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 500×670×128 mm ISO 15 envelope and equivalent catalogue C/C0; C 39/500 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 C39-500-M model number is decoded
In SKF catalogue PUB BU/P1 17000, C 39/500 M denotes a toroidal roller bearing whose 128 mm long rollers crown at both ends: the contact accepts angular misalignment while the ring positions float, which is why CARB bearings are specified at the free shaft end. In C 39/500 M the 39 dimension series fixes the 670 mm OD and 128 mm width around the 500 mm bore (the bore is written directly after the slash (no bore code)); the suffix M then selects the cylindrical bore for direct shaft fitting, machined brass M cage. 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. Speed planning separates the 700 r/min thermal reference from the 950 r/min mechanical limiting speed. The full-complement V executions carry more load but list no thermal reference speed; the brass-caged executions run faster and cooler at light load. 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
- 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
- brinelling of washer raceways from impact or mounting force applied through the rolling elements
- grease churning and overheating when a high-speed thrust position is over-packed
Selection pitfalls — read before you substitute
- Above 200 mm bore these bearings weigh tens of kilograms (125 kg here) — lifting gear and induction heating are mandatory, and a cocked ring scores the toroidal raceway before start-up.
- Reference and limiting speeds are different limits: the 700 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.
- The quoted 3150/6300 kN ratings belong to this exact execution (C 39/500 M); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.
- Never use C 39/500 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.
- Tapered-bore K executions mount on adapter sleeves (1:12) and K30 on withdrawal sleeves (1:30) — the 500 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- The 3150/6300 kN ratings and 125000 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 are the dimensions and ratings of the C 39/500 M?
A C 39/500 M measures 500 mm bore × 670 mm outside diameter × 128 mm width (19.685 × 26.378 × 5.039 in). From SKF catalogue PUB BU/P1 17000: dynamic C 3150 kN, static C0 6300 kN, fatigue limit Pu 430 kN, reference speed 700 r/min, limiting speed 950 r/min, mass about 125000 g.
Can a CARB bearing like C 39/500 M locate the shaft axially?
No — that is the defining feature. C 39/500 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 39/500 M designation read?
C = CARB toroidal family; 39 = dimension series; 500 mm (slash-size) = 500 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 (3150 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 39/500 M is the cylindrical bore for direct shaft fitting, machined brass M cage.
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.