61905-FAG bearing: complete specifications & equivalents

Specification table

Source: catalog reference (HR 1 Rolling Bearings (Jan 2020)) · extracted 2026-09-25

Parameters extracted from the official FAG Rolling Bearings catalogue (HR 1 Rolling Bearings (Jan 2020)); FAG® is a trademark of Schaeffler Technologies AG & Co. KG, used here for identification only — mpnbase is not an authorized FAG/Schaeffler distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at schaeffler.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 61905-FAG 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 Schaeffler HR 1 catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes 2Z (steel shields), 2RZ (non-contact rubber seals) and 2RSR (lip-contact rubber seals).

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 61905-FAG; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
• 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.
• Storage matters for open bearings: 61905-FAG 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 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-FAG.
• Shaft and housing fillets must clear the bearing chamfer so the 9 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
• The open 61905 has no integral sealing; in the Schaeffler HR 1 catalogue the protected variants carry suffixes 2Z (two steel shields), 2RZ (two non-contact rubber seals) and 2RSR (two lip-contact rubber seals). Do not confuse FAG's 2RZ with a contact seal — the RZ lip does not touch the inner ring, which is why its speed capability stays close to the open bearing.
• FAG rates 61905 at 24200 r/min mechanical limiting speed (thermal reference speed 13500 r/min) — a high-speed range where the thermal reference speed governs continuous duty; use low-viscosity turbine oil or high-speed grease and avoid lip-contact seals entirely.
• The 25 mm bore puts 61905 in Schaeffler's light industrial range; the standard cage and CN clearance cover most fractional-horsepower motor and small-pump duty, and FAG's X-life generation of these sizes carries higher ratings than legacy HR 1 printings — check the current eKatalog listing before reordering.
• FAG rates 61905 at 7.01 kN dynamic (C) and 4.55 kN static (C0); this light-to-medium rating suits fractional-horsepower drives and instruments — verify the equivalent dynamic load stays well below C for conveying or gearbox duty with shock.
• At only 42 g, 61905 is a lightweight FAG bearing that can be handled by hand; still press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.
• The 25×42×9 mm envelope of 61905 gives a D/d ratio of 1.68 and 8.5 mm radial section height — a thin FAG section that saves space but is sensitive to misalignment and shock; keep the housing round within IT7 and the shaft deflection below the raceway contact envelope.
• The 7.01/4.55 kN load ratings, mass 42 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 61905-FAG on the 25×42×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61905 in a rated drive. Where FAG has since released an X-life version of this size, its expanded C/C0 ratings supersede the HR 1 print values quoted here.
• Schaeffler's medias/eKatalog is the live source for the current execution of 61905: cage material, seal lip design and ratings can be revised between catalogue generations without any designation change.
• Schaeffler has moved many HR 1 sizes to the X-life generation with higher C/C0 ratings; the designation is unchanged, so a current eKatalog listing for 61905 may quote higher values than the HR 1 print figures on this page — the envelope is identical either way.