61903-2RS bearing: complete specifications & equivalents
The 61903-2RS is a ISO 15 radial bearing sized 17 x 30 x 7 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 | 17 mm |
| Outer diameter D | 30 mm |
| Width B | 7 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 | 4.62 kN |
| Basic static load rating C0 | 2.55 kN |
| Fatigue load limit Pu | 0.108 kN |
| Limiting speed (mechanical) | 14000 rpm |
| Operating temperature | -30 to +110 °C |
| Mass | 17 g |
| Manufacturer designation | SKF 61903-2RS1 |
| 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 | 0.669 in |
|---|---|
| Outer diameter D | 1.181 in |
| Width B | 0.276 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 6.5 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) | 11 of 63 |
| Bore above smallest 61900-series size | 14 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61903-2RS-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. |
| 61903-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; seal variant differs (2RS vs OPEN) — confirm sealing suits the duty. |
| 61903-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; seal variant differs (2RS vs ZZ) — confirm sealing suits the duty. |
| 61903 | 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. |
| 61903-2RS-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. |
| 61903-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; seal variant differs (2RS vs OPEN) — confirm sealing suits the duty. |
| 61903-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; seal variant differs (2RS vs RSR) — confirm sealing suits the duty. |
| 61903-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; seal variant differs (2RS vs ZZ) — confirm sealing suits the duty. |
| 61903-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61903-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; seal variant (2RS vs OPEN) and load ratings differ — confirm sealing and rating before substituting. |
| 61903-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; seal variant (2RS vs RSR) and load ratings differ — confirm sealing and rating before substituting. |
| 61903-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×30×7 mm envelope per ISO 15; seal variant (2RS vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| W61903-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61903-2RS1 shares the 17×30×7 mm envelope but rates differently (4.62/2.55 kN vs 3.97/2.55 kN) — not a load-rating equivalent. |
| W61903-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61903-2Z shares the 17×30×7 mm envelope but rates differently (4.62/2.55 kN vs 3.97/2.55 kN) — not a load-rating equivalent. |
| W61903 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61903 shares the 17×30×7 mm envelope but rates differently (4.62/2.55 kN vs 3.97/2.55 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 61903-2RS model number is decoded
In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61903 carries bore code 03 = 17 mm. Codes 00–03 follow the 10/12/15/17 mm exception table rather than code × 5. Outside diameter 30 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. SKF's contact-seal catalogue number is 61903-2RS1 (older text: -2RS1), mapped here from the industry-neutral -2RS spelling.
Typical equipment & failure modes
Common applications
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
- textile machinery
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)
- edge loading from shaft deflection or housing misalignment
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- Bore codes 00–03 use the exception table: 61903 fits a 17 mm shaft — the code × 5 mnemonic does not apply below code 04 (it would imply 0 mm for code 00).
- The 619xx thin section (6.5 mm section height at 17 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: 61903-2RS runs slower and cooler-limited than the open 61903; 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 61903-2RS in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.
- Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
- Deep-groove ball bearings tolerate only minutes of misalignment; if the 30 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61903-2RS.
- SKF catalogues the contact-sealed version as 61903-2RS1 (older printings may read -2RS1); it is shipped pre-greased and its 14000 r/min limiting speed is set by seal-lip drag and grease life versus the open bearing's 50000 r/min thermal reference speed.
- The 4.62/2.55 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 61903-2RS bearing?
A 61903-2RS deep-groove ball bearing has a 17 mm bore, 30 mm outer diameter and 7 mm width (0.669 × 1.181 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased.
How does the 61900 compare with other series at the same 17 mm bore?
619 is a thin section one step above 618: 30×7 mm with a 6.5 mm radial section at 17 mm bore; a 6203 on the same bore is substantially larger and more heavily rated.
Are 61903 bearings from different brands interchangeable?
For boundary dimensions, yes: every brand's 61903 uses the same ISO 15 envelope (17×30×7 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 internal clearance does 61903-2RS have?
Unless a clearance suffix says otherwise, 61903-2RS 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 61903 and verify the residual clearance after mounting.
What is the SKF designation and catalogue data for 61903-2RS?
In the SKF Rolling Bearings catalogue this size is listed as 61903-2RS1 — two contact elastomer seals over a lifetime grease fill, 17×30×7 mm per ISO 15. Quoted values: C 4.62 kN, C0 2.55 kN, Pu 0.108 kN, limiting speed 14000 r/min, mass 17 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61903-2RS.
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.