C5918-MB bearing: complete specifications & equivalents
The C5918-MB is a ISO 15 radial bearing sized 90 x 125 x 46 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 90 mm |
| Outer diameter D | 125 mm |
| Width B | 46 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 193 kN |
| Basic static load rating C0 | 325 kN |
| Fatigue load limit Pu | 37.5 kN |
| Reference speed (thermal) | 2600 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1750 g |
| Manufacturer designation | C 5918 MB |
| 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 & C5900-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 4.921 in |
| Width B | 1.811 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 17.5 mm |
| Smallest bore in C5900-series | 75 mm |
| Largest outer diameter in C5900-series | 125 mm |
| Width range across C5900-series | 40–46 mm |
| Bore position in C5900-series (smallest first) | 2 of 2 |
| Bore above smallest C5900-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| C5918-2CS5V-GEM9 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 90×125×46 mm envelope, but catalogue C/C0 differ between the cylindrical-bore MB inner-ring-guided brass-caged and cylindrical-bore sealed full-complement V executions (193/325 kN vs 224/400 kN) — envelope match, not a load-rating equivalent. |
| C5918-V | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 90×125×46 mm envelope, but catalogue C/C0 differ between the cylindrical-bore MB inner-ring-guided brass-caged and cylindrical-bore full-complement V executions (193/325 kN vs 224/400 kN) — envelope match, not a load-rating equivalent. |
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 C5918-MB model number is decoded
The CARB bearing C 5918 MB combines the self-aligning behaviour of a spherical roller bearing with the axial freedom of a cylindrical bearing in one 90 mm bore, 125 mm outside diameter, 46 mm wide unit rated 193 kN dynamic. The designation C 5918 MB separates into C (CARB), 59 (dimension series), 18 (90 mm bore) and MB (cylindrical bore for direct shaft fitting, machined inner-ring-guided brass cage (MB)); envelope 90×125×46 mm follows the ISO 15 plan. The MB suffix is a machined two-piece brass cage guided on the inner ring, the standard choice for wide, large-bore CARB sizes where a polymer cage would run beyond its temperature or load limit. The 1750 g mass over the 90×125×46 mm envelope yields about 2.14 kN dynamic per millimetre of bore — the long toroidal rollers give this family its radial capacity density. Seat tolerances follow the ISO 15 recommendation for the normal-load position — the 125 mm outer ring typically takes a loose housing fit to preserve float, and the rings must be supported across their full faces.
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
- 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
- rolling-contact fatigue spalling after the catalogue L10 life is exhausted
- grease churning and overheating when a high-speed thrust position is over-packed
Selection pitfalls — read before you substitute
- At 90 mm bore, shaft expansion is already measurable: calculate the required float inside the 46 mm wide bearing rather than assuming the free-end clearance is "enough" at operating temperature.
- Never use C 5918 MB 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 90 mm bore changes the sleeve family, and the drive-up procedure differs accordingly.
- Reference and limiting speeds are different limits: the 2,600 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 193/325 kN ratings belong to this exact execution (C 5918 MB); VE240 vibrating-screen variants and sealed 2CS/2NS variants have their own figures even at the same envelope.
- The 193/325 kN ratings and 1750 g mass are SKF catalogue values transcribed from ch. 10.1 of PUB BU/P1 17000 (PDF table page 860); 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
How is C 5918 MB mounted?
Slide or heat (max 120 °C) the bearing onto the 90 mm seat, give the outer ring a loose housing fit, leave the float travel unobstructed, and never press through the 46 mm roller set.
What are the dimensions and ratings of the C 5918 MB?
A C 5918 MB measures 90 mm bore × 125 mm outside diameter × 46 mm width (3.543 × 4.921 × 1.811 in). From SKF catalogue PUB BU/P1 17000: dynamic C 193 kN, static C0 325 kN, fatigue limit Pu 37.5 kN, reference speed 2,600 r/min, limiting speed 4,000 r/min, mass about 1750 g.
Can a CARB bearing like C 5918 MB locate the shaft axially?
No — that is the defining feature. C 5918 MB 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 5918 MB designation read?
C = CARB toroidal family; 59 = dimension series; 18 = 90 mm bore (code 18 × 5); suffix MB selects cylindrical bore for direct shaft fitting, machined inner-ring-guided brass cage (MB). K is a 1:12 tapered bore for an adapter sleeve, K30 a 1:30 bore for a withdrawal sleeve.
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.