6018-M (brass cage) bearing: complete specifications & equivalents
The 6018-M is a ISO 15 radial bearing sized 90 x 140 x 24 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 | 140 mm |
| Width B | 24 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 60.5 kN |
| Basic static load rating C0 | 50 kN |
| Fatigue load limit Pu | 1.96 kN |
| Reference speed (thermal) | 10000 rpm |
| Limiting speed (mechanical) | 8500 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1350 g |
| Manufacturer designation | 6018 M |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); 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 & 6000-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 0.945 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 6000-series | 4 mm |
| Largest outer diameter in 6000-series | 1150 mm |
| Width range across 6000-series | 4–155 mm |
| Bore position in 6000-series (smallest first) | 25 of 61 |
| Bore above smallest 6000-series size | 86 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6018-2RS-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6018DDU on the same 90×140×24 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 6018-RSR | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6018VV on the same 90×140×24 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 6018-ZZ-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6018ZZ on the same 90×140×24 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 6018-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6018 on the same 90×140×24 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 6018 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6018 (open arrangement) shares the 90×140×24 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
| 6018-ZZ | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6018-2Z (two non-contact shields) shares the 90×140×24 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
| 6018-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6018-2RS1 (two contact elastomer seals) shares the 90×140×24 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
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 6018-M model number is decoded
In the 6000-series, the last two digits encode the bore: 6018 carries code 18 = 90 mm (code × 5). The envelope is 90×140×24 mm (3.543×5.512×0.945 in) with a 25.0 mm radial section height, C 60.5 kN, C0 50 kN and Pu 1.96 kN. The open 6018 M carries no shields or seals and relies on application lubrication and external sealing. The M suffix identifies the machined brass cage execution, a separate order number from the pressed-steel version. Limiting speed 8500 r/min, catalogue mass 1350 g.
Typical equipment & failure modes
Common applications
- material-handling equipment
- industrial fans
- compressor drives
- machine tool auxiliaries
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- electrical pitting in VFD-driven motors without shaft grounding
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- At 90 mm bore, C3 clearance is the safe choice when interference fits plus temperature rise consume the CN clearance; a hot tight bearing with no residual clearance fails fast.
- The fatigue load limit is 1.96 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- The M suffix on 6018-M denotes a machined brass cage: it is the choice for high speeds, marginal lubrication and shock/vibration duty, and it is temperature-tolerant where polymer cages are not — the 1350 g quoted mass includes the heavier cage.
- Open 6018-M needs external sealing at the arrangement level; in dusty housings its life depends entirely on those external seals and the regreasing schedule.
- Plan a relubrication interval for 6018-M; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Catalogue ratings for 6018-M (C 60.5 kN, C0 50 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
- For positions that need relubrication, choose the open execution of 6018 and design the housing with a grease path; shielded and sealed versions are intended as fit-and-forget units.
- Where two 6018 bearings share one shaft in a preloaded or matched arrangement, order both from the same production lot; catalogue figures describe a single bearing, not a matched set.
Frequently asked questions
What are the dimensions of 6018-M?
The SKF 6018 M measures 90 mm bore × 140 mm OD × 24 mm width (3.543 × 5.512 × 0.945 in), mass about 1350 g. It is open, with no shields or seals.
How does the bore code in 6018 work?
The final two digits of 6018 are bore code 18, multiplied by 5 to give 90 mm.
How long can a greased 6018-M be stored?
Sealed and shielded SKF units carry a finite grease shelf life: SKF recommends first-in-first-out stock rotation and dry, cool, vibration-free storage. Open units ship with rust preventive only and are greased at assembly.
What load can 6018-M take?
Catalogue values for 6018 M: dynamic C 60.5 kN, static C0 50 kN, fatigue limit Pu 1.96 kN. Use C in life calculation and C0 for static checks at 90 mm bore.
What is the speed rating of 6018-M?
SKF lists a 10000 r/min thermal reference speed and a 8500 r/min mechanical limiting speed for 6018 M; real limits also depend on lubrication and fits.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.