61901-2RS bearing: complete specifications & equivalents
The 61901-2RS is a ISO 15 radial bearing sized 12 x 24 x 6 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 | 12 mm |
| Outer diameter D | 24 mm |
| Width B | 6 mm |
| Material | GCr15 |
| Seal / shield | 2RS |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 2.91 kN |
| Basic static load rating C0 | 1.46 kN |
| Fatigue load limit Pu | 0.062 kN |
| Limiting speed (mechanical) | 19000 rpm |
| Operating temperature | -30 to +110 °C |
| Mass | 11 g |
| Manufacturer designation | SKF 61901-2RS1 |
| 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 | 0.472 in |
|---|---|
| Outer diameter D | 0.945 in |
| Width B | 0.236 in |
| ISO bore code | 01 |
| Radial section height (D−d)/2 | 6 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) | 9 of 63 |
| Bore above smallest 61900-series size | 9 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61901-2RS-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. |
| 61901-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×24×6 mm envelope per ISO 15; seal variant differs (2RS vs OPEN) — confirm sealing suits the duty. |
| 61901-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×24×6 mm envelope per ISO 15; seal variant differs (2RS vs ZZ) — confirm sealing suits the duty. |
| 61901 | ISO 15 | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting. |
| 61901-2RS-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. |
| 61901-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×24×6 mm envelope per ISO 15; seal variant differs (2RS vs OPEN) — confirm sealing suits the duty. |
| 61901-RSR | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×24×6 mm envelope per ISO 15; seal variant differs (2RS vs RSR) — confirm sealing suits the duty. |
| 61901-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×24×6 mm envelope per ISO 15; seal variant differs (2RS vs ZZ) — confirm sealing suits the duty. |
| 61901-2RS-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. |
| 61901-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×24×6 mm envelope per ISO 15; seal variant differs (2RS vs OPEN) — confirm sealing suits the duty. |
| 61901-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×24×6 mm envelope per ISO 15; seal variant differs (2RS vs RSR) — confirm sealing suits the duty. |
| 61901-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×24×6 mm envelope per ISO 15; seal variant differs (2RS vs ZZ) — confirm sealing suits the duty. |
| W61901-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61901-2RS1 shares the 12×24×6 mm envelope but rates differently (2.91/1.46 kN vs 2.51/1.46 kN) — not a load-rating equivalent. |
| W61901-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61901-2Z shares the 12×24×6 mm envelope but rates differently (2.91/1.46 kN vs 2.51/1.46 kN) — not a load-rating equivalent. |
| W61901 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61901 shares the 12×24×6 mm envelope but rates differently (2.91/1.46 kN vs 2.51/1.46 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 61901-2RS model number is decoded
61901-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the thin 619xx section (diameter series 9 of ISO 15), its bore code 01 comes from the 10/12/15/17 mm exception table, giving a 12 mm bore; the 24 mm outside diameter and 6 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. SKF's contact-seal catalogue number is 61901-2RS1 (older text: -2RS1), mapped here from the industry-neutral -2RS spelling.
Typical equipment & failure modes
Common applications
- packaging machinery
- space-constrained gearboxes
- clutch and transmission assemblies
- robotics and automation joints
Known failure patterns
- seal-lip hardening and loss of pre-grease in sustained high-temperature service
- grease-life expiry in the sealed-for-life cavity (no relubrication path)
- raceway smearing under marginal lubrication at start-up
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Codes 00–03 are the exception series: 61901 takes its 12 mm bore from the 10/12/15/17 mm table, so two designations only a few millimetres apart can read alike on paper — order by measured shaft size, not by code arithmetic.
- The 619xx thin section (6.0 mm section height at 12 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- Contact seals add drag and heat: 61901-2RS runs slower and cooler-limited than the open 61901; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
- Never wash a sealed 61901-2RS in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 24 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61901-2RS.
- Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 6 mm-wide ring of 61901-2RS drags the lip and overheats it.
- SKF catalogues the contact-sealed version as 61901-2RS1 (older printings may read -2RS1); it is shipped pre-greased and its 19000 r/min limiting speed is set by seal-lip drag and grease life versus the open bearing's 67000 r/min thermal reference speed.
- The 2.91/1.46 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 61901-2RS bearing?
A 61901-2RS deep-groove ball bearing has a 12 mm bore, 24 mm outer diameter and 6 mm width (0.472 × 0.945 × 0.236 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased.
How should 61901-2RS be mounted?
Apply the mounting force to the ring being fitted: on a 12 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 61901-2RS need?
61901-2RS is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61901 with a housing grease fitting instead.
Why does 61901 not follow the bore-code × 5 rule?
Codes 00–03 use the exception table (10, 12, 15 and 17 mm): 61901 with code 01 has a 12 mm bore. The code × 5 convention starts at code 04 (20 mm).
What is the SKF designation and catalogue data for 61901-2RS?
In the SKF Rolling Bearings catalogue this size is listed as 61901-2RS1 — two contact elastomer seals over a lifetime grease fill, 12×24×6 mm per ISO 15. Quoted values: C 2.91 kN, C0 1.46 kN, Pu 0.062 kN, limiting speed 19000 r/min, mass 11 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61901-2RS.
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.