61803 bearing: complete specifications & equivalents
The 61803 is a ISO 15 radial bearing sized 17 x 26 x 5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 17 mm |
| Outer diameter D | 26 mm |
| Width B | 5 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 | 2.03 kN |
| Basic static load rating C0 | 1.27 kN |
| Fatigue load limit Pu | 0.054 kN |
| Reference speed (thermal) | 56000 rpm |
| Limiting speed (mechanical) | 34000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 8 g |
| Manufacturer designation | SKF 61803 |
| 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 | 0.669 in |
|---|---|
| Outer diameter D | 1.024 in |
| Width B | 0.197 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 4.5 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) | 14 of 74 |
| Bore above smallest 61800-series size | 16 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61803-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; seal variant (OPEN vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61803-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61803-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; seal variant (OPEN vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| 61803 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
| 61803-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; seal variant (OPEN vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61803-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61803-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting. |
| 61803-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; seal variant (OPEN vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| 61803-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; seal variant (OPEN vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 61803-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 61803-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting. |
| 61803-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×26×5 mm envelope per ISO 15; seal variant (OPEN vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| W61803-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61803-2RS1 shares the 17×26×5 mm envelope but rates differently (2.03/1.27 kN vs 1.78/1.27 kN) — not a load-rating equivalent. |
| W61803-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 61803-2Z shares the 17×26×5 mm envelope but rates differently (2.03/1.27 kN vs 1.78/1.27 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 61803 model number is decoded
61803 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), its bore code 03 comes from the 10/12/15/17 mm exception table, giving a 17 mm bore; the 26 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 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. 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
- space-constrained gearboxes
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- false brinelling from vibration while the shaft is stationary
- fretting corrosion on a loose shaft seat
Selection pitfalls — read before you substitute
- Miniature bearings like 61803 (17 mm bore) brinell under surprisingly small pressing force; use a fitting sleeve on the ring being mounted and never let the assembly load cross the balls.
- The 618xx thin section at 17 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6203.
- The open 61803 has no lubricant retention: grease escapes and contaminants migrate straight into the 17×26×5 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Storage matters for open bearings: 61803 leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
- Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- Never mix components between two 61803 units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
- The open 61803 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61803-2Z (shields) and 61803-2RSH (contact seals), not suffix-free 61803.
- The 2.03/1.27 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 61803 bearing?
A 61803 deep-groove ball bearing has a 17 mm bore, 26 mm outer diameter and 5 mm width (0.669 × 1.024 × 0.197 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How should 61803 be mounted?
Apply the mounting force to the ring being fitted: on a 17 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 61803 need?
The open 61803 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.
Why does 61803 not follow the bore-code × 5 rule?
Codes 00–03 use the exception table (10, 12, 15 and 17 mm): 61803 with code 03 has a 17 mm bore. The code × 5 convention starts at code 04 (20 mm).
What is the SKF designation and catalogue data for 61803?
In the SKF Rolling Bearings catalogue this size is listed as 61803 — the open (unsealed) execution, 17×26×5 mm per ISO 15. Quoted values: C 2.03 kN, C0 1.27 kN, Pu 0.054 kN, limiting speed 34000 r/min, mass 8 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 61803.
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.