61801-ZZ-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-ZZ-FAG model number is decoded

In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61801 carries bore code 12 = 12 mm. Outside diameter 21 mm and width 5 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. 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. Schaeffler HR 1 catalogue order number: 61801-2Z (FAG suffix 2Z), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.

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 61801 with C3 for those conditions.
• 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.
• ZZ shields are non-contact: 61801-ZZ-FAG blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61801-2RS for that.
• Do not wash 61801-ZZ-FAG in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.
• Never mix components between two 61801-ZZ-FAG units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
• Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.
• Schaeffler HR 1 lists the shielded version as 61801-2Z — FAG suffix 2Z, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the FAG order number when buying through a Schaeffler channel.
• The 42500 r/min mechanical limiting speed puts 61801 at the top of the HR 1 deep-groove speed range (thermal reference speed 23500 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 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 6 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 6 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 61801-2Z 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.
• For hot shafts above roughly 100 °C continuous, consult Schaeffler about seal material and grease options for the 2RSR execution of 61801; the standard NBR lip is the economical general-duty choice, not the high-temperature one.
• 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.