61805-RSR bearing: complete specifications & equivalents
The 61805-RSR is a ISO 15 radial bearing sized 25 x 37 x 7 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 | 37 mm |
| Width B | 7 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 | 4.36 kN |
| Basic static load rating C0 | 2.6 kN |
| Fatigue load limit Pu | 0.125 kN |
| Reference speed (thermal) | 38000 rpm |
| Limiting speed (mechanical) | 19000 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 22 g |
| Manufacturer designation | SKF 61805-2RZ |
| 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 & 61800-series range
| Bore d | 0.984 in |
|---|---|
| Outer diameter D | 1.457 in |
| Width B | 0.276 in |
| ISO bore code | 05 |
| Radial section height (D−d)/2 | 6 mm |
| Smallest bore in 61800-series | 1 mm |
| Largest outer diameter in 61800-series | 1820 mm |
| Width range across 61800-series | 1–140 mm |
| Bore position in 61800-series (smallest first) | 16 of 74 |
| Bore above smallest 61800-series size | 24 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61805-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61805-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs OPEN) and load ratings differ — confirm sealing and rating before substituting. |
| 61805-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| 61805-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61805-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs OPEN) and load ratings differ — confirm sealing and rating before substituting. |
| 61805-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61805-ZZ | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| 61805-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61805-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs OPEN) and load ratings differ — confirm sealing and rating before substituting. |
| 61805-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61805-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×37×7 mm envelope per ISO 15; seal variant (RSR vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| W61805-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61805-2RS1 shares the 25×37×7 mm envelope but rates differently (4.36/2.6 kN vs 3.38/2.5 kN) — not a load-rating equivalent. |
| W61805-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61805-2Z shares the 25×37×7 mm envelope but rates differently (4.36/2.6 kN vs 3.38/2.5 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 61805-RSR model number is decoded
61805-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 37 mm outside diameter and 7 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 61805-2RZ.
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
- fretting corrosion on a loose shaft seat
- cage damage from operation beyond the limiting speed
Selection pitfalls — read before you substitute
- At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61805-RSR; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
- Only 6.0 mm of radial section separates bore and OD on the 618xx series at 25 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6205.
- The low-drag lip of 61805-RSR barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.
- The non-contact lip of 61805-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.
- A 25 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
- Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.
- SKF catalogues the low-friction seal as 61805-2RZ (suffix -2RSL or -2RZ): a non-contact elastomer lip that runs near the open 19000 r/min limiting speed, closer to the open bearing's 38000 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 4.36/2.6 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 61805-RSR bearing?
A 61805-RSR deep-groove ball bearing has a 25 mm bore, 37 mm outer diameter and 7 mm width (0.984 × 1.457 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals.
What does the RSR suffix on 61805-RSR mean?
RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments.
How does the 61800 compare with other series at the same 25 mm bore?
618 is an extra-thin section: 37×7 mm, only 6.0 mm radial section at 25 mm bore, far smaller than a 6205, for space-limited layouts at the cost of load rating and misalignment tolerance.
Are 61805 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 61805 uses the same ISO 15 envelope (25×37×7 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 is the SKF designation and catalogue data for 61805-RSR?
In the SKF Rolling Bearings catalogue this size is listed as 61805-2RZ — two low-friction non-contact elastomer seals, 25×37×7 mm per ISO 15. Quoted values: C 4.36 kN, C0 2.6 kN, Pu 0.125 kN, limiting speed 19000 r/min, mass 22 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61805-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.