61905-RSR bearing: complete specifications & equivalents
The 61905-RSR is a ISO 15 radial bearing sized 25 x 42 x 9 mm (bore x OD x width) with RSR 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 | GCr15 |
| Seal / shield | RSR |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 7.02 kN |
| Basic static load rating C0 | 4.3 kN |
| Fatigue load limit Pu | 0.193 kN |
| Reference speed (thermal) | 36000 rpm |
| Limiting speed (mechanical) | 18000 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 45 g |
| Manufacturer designation | SKF 61905-2RZ |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-24 |
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 & 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 |
|---|---|---|---|
| 61905-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant differs (RSR vs 2RS) — confirm sealing suits the duty. |
| 61905-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant differs (RSR vs OPEN) — confirm sealing suits the duty. |
| 61905-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant differs (RSR vs ZZ) — confirm sealing suits the duty. |
| 61905-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant differs (RSR vs 2RS) — confirm sealing suits the duty. |
| 61905-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant differs (RSR vs OPEN) — confirm sealing suits the duty. |
| 61905-RSR-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. |
| 61905-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant differs (RSR vs ZZ) — confirm sealing suits the duty. |
| 61905-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant (RSR vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61905-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant (RSR vs OPEN) and load ratings differ — confirm sealing and rating before substituting. |
| 61905-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61905-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant (RSR vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| W61905-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61905-2RS1 shares the 25×42×9 mm envelope but rates differently (7.02/4.3 kN vs 6.05/4.5 kN) — 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 61905-RSR model number is decoded
61905-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 42 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. SKF's low-friction seal suffix is 2RSL/2RZ (this page's industry-neutral spelling is -RSR); catalogue number 61905-2RZ.
Typical equipment & failure modes
Common applications
- lay shafts and idler shafts
- textile machinery
- packaging machinery
- space-constrained gearboxes
Known failure patterns
- ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)
- lip-lubricant starvation if the bearing runs dry for extended periods
- electrical pitting in VFD-driven motors without grounding protection
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- A 25 mm shaft for 61905 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.
- The 619xx thin section at 25 mm bore (8.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.
- RSR low-friction seals on 61905-RSR run faster than contact-seal 61905-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61905-2RS instead.
- The non-contact lip of 61905-RSR does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 25 mm bore position before relying on it as sealed-for-life.
- Never mix components between two 61905-RSR units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
- Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 9 mm-wide ring of 61905-RSR drags the lip and overheats it.
- SKF catalogues the low-friction seal as 61905-2RZ (suffix -2RSL or -2RZ): a non-contact elastomer lip that runs near the open 18000 r/min limiting speed, closer to the open bearing's 36000 r/min reference than the contact-seal version. It keeps coarse debris out without the drag of a contact seal, but is not liquid-tight — use 2RSH for wet or fine-dust positions.
- The 7.02/4.3 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 61905-RSR bearing?
A 61905-RSR deep-groove ball bearing has a 25 mm bore, 42 mm outer diameter and 9 mm width (0.984 × 1.654 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
Are 61905 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 61905 uses the same ISO 15 envelope (25×42×9 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar).
What internal clearance does 61905-RSR have?
Unless a clearance suffix says otherwise, 61905-RSR is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61905 and verify the residual clearance after mounting.
How should 61905-RSR be mounted?
Apply the mounting force to the ring being fitted: on a 25 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 is the SKF designation and catalogue data for 61905-RSR?
In the SKF Rolling Bearings catalogue this size is listed as 61905-2RZ — two low-friction non-contact elastomer seals, 25×42×9 mm per ISO 15. Quoted values: C 7.02 kN, C0 4.3 kN, Pu 0.193 kN, limiting speed 18000 r/min, mass 45 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61905-RSR.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-24. Read our editorial & correction policy.