61901-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 61901-FAG model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61901 carries bore code 12 = 12 mm. Outside diameter 24 mm and width 6 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 12 mm shaft, typical catalogue practice is a j5 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

• Temperature rise and interference fits consume internal clearance on this 12 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61901 with C3 for those conditions.
• 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.
• Storage matters for open bearings: 61901-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 61901 units.
• Measure the shaft, do not trust the drawing: a 12 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61901-FAG.
• Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
• The open 61901 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.
• The 45000 r/min mechanical limiting speed puts 61901 at the top of the HR 1 deep-groove speed range (thermal reference speed 23300 r/min); at these speeds cage design and grease shear dominate — run open with oil-mist or air-over-oil lubrication and verify the thermal reference speed for the actual load before committing.
• At 12 mm bore the 61901 sits in Schaeffler's small-bore range; HR 1 ships these sizes with a pressed steel or plastic cage and P0 tolerance as standard — for instrument or spindle accuracy order the P6/P5 variant explicitly, since P0 runout figures will not hold.
• At 2.89 kN dynamic load rating (C) and 1.46 kN static (C0), 61901 is a light-load FAG bearing: L10 life above a few kN of equivalent load is short, so size up to a 62-series on the same bore if the duty sees shock or frequent starts.
• At only 12 g, 61901 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 12×24×6 mm envelope of 61901 gives a D/d ratio of 2.00 and 6.0 mm radial section height — a heavy FAG section for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.
• The 2.89/1.46 kN load ratings, mass 12 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 61901-FAG on the 12×24×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61901 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 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 61901 may quote higher values than the HR 1 print figures on this page — the envelope is identical either way.
• Schaeffler's medias/eKatalog is the live source for the current execution of 61901: cage material, seal lip design and ratings can be revised between catalogue generations without any designation change.