61801-2RS-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 61801-2RS-FAG model number is decoded

61801-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 12 by five gives the 12 mm bore; the 21 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 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. Schaeffler HR 1 catalogues the lip-contact sealed version as 61801-2RSR (FAG suffix 2RSR), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 12 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61801 against the shaft shoulder while it cools so the ring cannot creep back.
• Only 4.5 mm of radial section separates bore and OD on the 618xx series at 12 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6212.
• Heat is the enemy of the sealed 61801-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.
• Never wash a sealed 61801-2RS-FAG in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.
• Never mix components between two 61801-2RS-FAG units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
• Shaft and housing fillets must clear the bearing chamfer so the 5 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
• Schaeffler HR 1 lists the lip-contact sealed version as 61801-2RSR (FAG suffix 2RSR), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing. FAG's RSR lip material is NBR as standard — above roughly 100 °C continuous, consult Schaeffler for higher-temperature seal options.
• FAG rates 61801 at 18100 r/min mechanical limiting speed — 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.
• At 12 mm bore the 61801 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 1.92 kN dynamic load rating (C) and 1.04 kN static (C0), 61801 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 7 g, 61801 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 12×21×5 mm envelope of 61801 gives a D/d ratio of 1.75 and 4.5 mm radial section height — a standard FAG medium section balancing load capacity and speed; the standard cage is adequate up to the listed speeds and C3 clearance is the common hot-shaft choice.
• The 1.92/1.04 kN load ratings, mass 7 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 61801-2RSR on the 12×21×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61801 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 61801: 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 61801 may quote higher values than the HR 1 print figures on this page — the envelope is identical either way.