W61905-2RS bearing: complete specifications & equivalents
The W61905-2RS is a ISO 15 radial bearing sized 25 x 42 x 9 mm (bore x OD x width) with 2RS sealing. Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 25 mm |
| Outer diameter D | 42 mm |
| Width B | 9 mm |
| Material | SS440C |
| Seal / shield | 2RS |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 6.05 kN |
| Basic static load rating C0 | 4.5 kN |
| Fatigue load limit Pu | 0.193 kN |
| Limiting speed (mechanical) | 10000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 40 g |
| Manufacturer designation | W 61905-2RS1 |
| 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 & 61900-series range
| Bore d | 0.984 in |
|---|---|
| Outer diameter D | 1.654 in |
| Width B | 0.354 in |
| ISO bore code | 05 |
| Radial section height (D−d)/2 | 8.5 mm |
| Smallest bore in 61900-series | 3 mm |
| Largest outer diameter in 61900-series | 1120 mm |
| Width range across 61900-series | 3–118 mm |
| Bore position in 61900-series (smallest first) | 13 of 63 |
| Bore above smallest 61900-series size | 22 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61905-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | NSK NSK 6905ZZ shares the 25×42×9 mm envelope but carries different catalogue ratings (6.05/4.5 kN vs 7.75/4.55 kN) — the stainless execution is not a load-rating equivalent. |
| 61905 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF SKF 61905 shares the 25×42×9 mm envelope but carries different catalogue ratings (6.05/4.5 kN vs 7.02/4.3 kN) — the stainless execution is not a load-rating equivalent. |
| 61905-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF SKF 61905-2RS1 shares the 25×42×9 mm envelope but carries different catalogue ratings (6.05/4.5 kN vs 7.02/4.3 kN) — the stainless execution is not a load-rating equivalent. |
| 61905-RSR | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF SKF 61905-2RZ shares the 25×42×9 mm envelope but carries different catalogue ratings (6.05/4.5 kN vs 7.02/4.3 kN) — the stainless execution is 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 W61905-2RS model number is decoded
The W prefix denotes SKF stainless steel deep-groove bearings (X108CrMo17 / AISI 440C class rings). In the 61900-series, the last two digits encode the bore: 61905 carries code 05 = 25 mm (code × 5). Envelope 25×42×9 mm (0.984×1.654×0.354 in), C 6.05 kN, C0 4.5 kN, Pu 0.193 kN; limiting speed 10000 r/min and mass 40 g. SKF catalogues the sealed execution as W 61905-2RS1: two contact elastomer lips (2RS1/2RSH spelling) over a lifetime grease fill; the lips add drag, and no reference (thermal) speed is published. Stainless is chosen for corrosion and washdown duty, not for extra load — the same-envelope chrome-steel bearing rates higher.
Typical equipment & failure modes
Common applications
- washdown-duty equipment
- chemical and marine atmospheres
- medical and laboratory devices
- small pumps handling corrosive media
Known failure patterns
- seal and grease failure before the rings corrode in sustained washdown service
- surface staining and pitting when even the stainless steel is left unlubricated in salty or acidic duty
- contact-seal lip hardening and pre-grease loss after long high-temperature service
- grease-life expiry inside the sealed-for-life cavity, which has no relubrication path
Selection pitfalls — read before you substitute
- The stainless steel is martensitic and MAGNETIC; do not reject W61905-2RS over magnetism — only austenitic grades are non-magnetic, and those are too soft for bearing raceways.
- Stainless bearings carry lower load ratings than chrome steel of the same envelope: W61905-2RS is quoted at C 6.05 kN versus the 9 mm-wide 52100 version — do not swap on dimensions alone.
- Food, pharmaceutical and washdown positions need food-grade grease (e.g. NSF H1 registered) inside W61905-2RS; standard fill is industrial grease unless specified otherwise.
- Corrosion resistance depends on clean, undamaged surfaces: never weld near W61905-2RS or scratch the raceways during mounting, since the damaged spot starts corrosion.
- Assign interference to the rotating ring: on a conventional shaft-mounted 25 mm position the inner ring rotates, so use a k5/m6 shaft seat with an H7 housing — reverse the logic if the outer ring rotates.
- Clearance suffixes follow the seal code in the designation stack (e.g. W 61905-2Z/C3 in SKF spelling); no suffix means normal CN internal clearance.
Frequently asked questions
What are the dimensions of the stainless W61905-2RS?
SKF W 61905-2RS1 measures 25×42×9 mm (0.984×1.654×0.354 in), about 40 g, C 6.05 kN.
What does the W in W 61905-2RS1 mean?
W is the SKF prefix for stainless steel deep-groove bearings (rings in X108CrMo17 / AISI 440C class); the rest of the designation follows the normal series and bore rules.
What grease is supplied in W61905-2RS?
Sealed units are pre-greased for life; for food or pharmaceutical duty order (or re-grease before service) with an NSF H1 registered food-grade grease.
Are W stainless bearings waterproof?
No — the stainless rings resist moisture and weak chemicals far better than 52100 chrome steel, but salt spray, strong chlorides and unlubricated washdown duty can still corrode W61905-2RS; add seals and food-grade grease for wet positions.
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.