6208 bearing: complete specifications & equivalents
The 6208 is a ISO 15 radial bearing sized 40 x 80 x 18 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 40 mm |
| Outer diameter D | 80 mm |
| Width B | 18 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 32.5 kN |
| Basic static load rating C0 | 19 kN |
| Fatigue load limit Pu | 0.8 kN |
| Reference speed (thermal) | 18000 rpm |
| Limiting speed (mechanical) | 11000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 370 g |
| Manufacturer designation | SKF 6208 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-25 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-24
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 & 6200-series range
| Bore d | 1.575 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 0.709 in |
| ISO bore code | 08 |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in 6200-series | 3 mm |
| Largest outer diameter in 6200-series | 540 mm |
| Width range across 6200-series | 2.5–85 mm |
| Bore position in 6200-series (smallest first) | 17 of 45 |
| Bore above smallest 6200-series size | 37 mm |
Mounting, lubrication & life for 6208
Recommended fits & mounting
- Rotating inner ring on a 40 mm shaft: k5; housing bore H7 for normal stationary-load outer rings. Reverse the logic if the outer ring rotates.
- Fit by induction heating (max 120 °C) where practical — never drive the ring home through the rolling elements.
- Keep shaft and housing fillet radii below the bearing chamfer so the 18 mm-wide ring seats square on its shoulder.
Lubrication strategy
Open execution: the application supplies lubrication. Use the grease relubrication chart for this bearing — pitch diameter dm = 60 mm, so the speed factor at the 11,000 r/min limiting speed is 660,000 mm·r/min. Intervals shorten steeply as that factor rises.
Worked L10 life example (illustrative duty)
For ball bearings, L10h = (C/P)3 · 106 / (60·n). Taking an example radial equivalent load P = 3 kN at n = 1,500 r/min (a small belted motor duty — substitute the real equivalent load from the application calculation):
C = 32.5 kN → L10h ≈ 14,127 hours
Choosing a section at the same 40 mm bore
| Series | Open execution | OD × width | C (kN) | Limiting speed (r/min) |
|---|---|---|---|---|
| 60xx | 6008-FAG | 68 × 15 | 17.8 | 14,600 |
| 62xx | 6208-FAG | 80 × 18 | 31.5 | 13,600 |
| 63xx | 6308-FAG | 90 × 23 | 47.0 | 11,800 |
| 64xx | 6408-FAG | 110 × 27 | 68.0 | 9,500 |
| 618xx | 61808-FAG | 52 × 7 | 4.9 | 19,300 |
| 619xx | 61908-FAG | 62 × 12 | 14.5 | 15,800 |
| 160xx | 16008 | 68 × 9 | 12.6 | 15,200 |
A larger section is not a drop-in swap — OD and width change — and same-envelope seal variants are compared on the 40×80×18 envelope page. Match meaning, not the size chart alone: see what the cross-reference levels mean.
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6208-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×18 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6208-FAG | FAG | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6208-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×18 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 6208 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
| 6208-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×18 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6208-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6208-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×18 mm envelope per ISO 15; seal variant differs (OPEN vs RSR) — confirm sealing suits the duty. |
| 6208-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×18 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 6208-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×18 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6208-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6208-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×18 mm envelope per ISO 15; seal variant differs (OPEN vs RSR) — confirm sealing suits the duty. |
| 6208-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 40×80×18 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 7208 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| NU208 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| 1726208-2RS1 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF 1726208-2RS1 is a standard-inner-ring insert on the same 40x80x18 mm ISO 15 envelope with ratings within 10 %, but its outer surface is sphered for a Y-housing whereas this page is the cylindrical-OD deep-groove bearing — not interchangeable mounts. |
| W6208-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6208-2RS1 shares the 40×80×18 mm envelope but rates differently (32.5/19 kN vs 25.1/17.6 kN) — not a load-rating equivalent. |
| W6208-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6208-2Z shares the 40×80×18 mm envelope but rates differently (32.5/19 kN vs 25.1/17.6 kN) — not a load-rating equivalent. |
| W6208 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6208 shares the 40×80×18 mm envelope but rates differently (32.5/19 kN vs 25.1/17.6 kN) — not a load-rating equivalent. |
| 208 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF 208 shares the 40×80×18 mm envelope but catalogue C/C0 differ — envelope match only after a load check. |
| 208-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF 208-2Z shares the 40×80×18 mm envelope but catalogue C/C0 differ — envelope match only after a load check. |
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 6208 model number is decoded
In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6208 carries bore code 08 = 40 mm. Outside diameter 80 mm and width 18 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the SKF catalogue this open execution carries the bare designation; protected variants are ordered separately as -2Z and -2RSH.
Typical equipment & failure modes
Common applications
- fans and blowers
- electric motors
- centrifugal pumps
- small gearboxes
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- false brinelling from vibration while the shaft is stationary
- fretting corrosion on a loose shaft seat
Selection pitfalls — read before you substitute
- At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6208; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
- At 40 mm bore the 62xx light series is the workhorse section; its 80×18 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.
- The open 6208 has no lubricant retention: grease escapes and contaminants migrate straight into the 40×80×18 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Storage matters for open bearings: 6208 leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
- Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
- Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- The open 6208 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 6208-2Z (shields) and 6208-2RSH (contact seals), not suffix-free 6208.
- The 32.5/19 kN ratings here are SKF Explorer-class figures from catalogue PUB BU/P1 17000/1 EN (Oct 2018); SKF can revise internal geometry and ratings without changing the designation, so treat the catalogue version and date as part of the specification and re-verify for critical drives.
Frequently asked questions
What are the dimensions of a 6208 bearing?
A 6208 deep-groove ball bearing has a 40 mm bore, 80 mm outer diameter and 18 mm width (1.575 × 3.15 × 0.709 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How should 6208 be mounted?
Apply the mounting force to the ring being fitted: on a 40 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals.
What lubrication does 6208 need?
The open 6208 is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval.
How does the 6208 bore code work?
The last two digits of 6208 are bore code 08, giving 08 × 5 = 40 mm bore. The 80 mm outside diameter and 18 mm width follow the ISO 15 diameter series, not the bore code alone.
What is the SKF designation and catalogue data for 6208?
In the SKF Rolling Bearings catalogue this size is listed as 6208 — the open (unsealed) execution, 40×80×18 mm per ISO 15. Quoted values: C 32.5 kN, C0 19 kN, Pu 0.8 kN, limiting speed 11000 r/min, mass 370 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6208.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-25. Read our editorial & correction policy.