61805 bearing: complete specifications & equivalents

Specification table

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.

Cross references & equivalents

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 model number is decoded

61805 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), 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. In the SKF catalogue this open execution carries the bare designation; protected variants are ordered separately as -2Z and -2RSH.

Typical equipment & failure modes

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; 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.
• Storage matters for open bearings: 61805 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.
• Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61805 units.
• 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.
• Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 7 mm-wide ring of 61805 drags the lip and overheats it.
• The open 61805 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 61805-2Z (shields) and 61805-2RSH (contact seals), not suffix-free 61805.
• 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.