61905 bearing: complete specifications & equivalents
The 61905 is a ISO 15 radial bearing sized 25 x 42 x 9 mm (bore x OD x width). 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 | open |
| 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) | 22000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 45 g |
| Manufacturer designation | SKF 61905 |
| 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 & 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 (OPEN vs 2RS) — confirm sealing suits the duty. |
| 61905-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. |
| 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 (OPEN 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 (OPEN vs 2RS) — confirm sealing suits the duty. |
| 61905-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-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 25×42×9 mm envelope per ISO 15; seal variant differs (OPEN vs RSR) — confirm sealing suits the duty. |
| 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 (OPEN 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 (OPEN 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; catalogue load ratings differ by >10% — re-rate the application 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; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating 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 (OPEN 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 model number is decoded
In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61905 carries bore code 05 = 25 mm. Outside diameter 42 mm and width 9 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 25 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
- lay shafts and idler shafts
- textile machinery
- packaging machinery
- space-constrained gearboxes
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- cage damage from operation beyond the limiting speed
- electrical pitting in VFD-driven motors without grounding protection
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 (8.5 mm section height at 25 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- The open 61905 has no lubricant retention: grease escapes and contaminants migrate straight into the 25×42×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61905 units.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 42 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61905.
- Suffixes stack in a defined order — clearance follows the seal code, e.g. 61905-C3. No clearance suffix means normal CN clearance.
- The open 61905 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61905-2Z (shields) and 61905-2RSH (contact seals), not suffix-free 61905.
- 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 bearing?
A 61905 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 an open bearing with no seals or shields.
How should 61905 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 lubrication does 61905 need?
The open 61905 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 61905 bore code work?
The last two digits of 61905 are bore code 05, giving 05 × 5 = 25 mm bore. The 42 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone.
What is the SKF designation and catalogue data for 61905?
In the SKF Rolling Bearings catalogue this size is listed as 61905 — the open (unsealed) execution, 25×42×9 mm per ISO 15. Quoted values: C 7.02 kN, C0 4.3 kN, Pu 0.193 kN, limiting speed 22000 r/min, mass 45 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61905.
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.