61821-RSR 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 61821-RSR model number is decoded

61821-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 21 by five gives the 105 mm bore; the 130 mm outside diameter and 13 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 105 mm shaft under normal load, catalogue practice seats it on a m6 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. SKF's low-friction seal suffix is 2RSL/2RZ (this page's industry-neutral spelling is -RSR); catalogue number 61821-2RZ.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Large bores like the 105 mm of 61821-RSR demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.
• The 618xx thin section at 105 mm bore has only a 12.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6221.
• RSR low-friction seals on 61821-RSR run faster than contact-seal 61821-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61821-2RS instead.
• The non-contact lip of 61821-RSR does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 105 mm bore position before relying on it as sealed-for-life.
• Suffixes stack in a defined order — clearance follows the seal code, e.g. 61821-C3. No clearance suffix means normal CN clearance.
• 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.
• SKF catalogues the low-friction seal as 61821-2RZ (suffix -2RSL or -2RZ): a non-contact elastomer lip that runs near the open 5000 r/min limiting speed, closer to the open bearing's 10000 r/min reference than the contact-seal version. It keeps coarse debris out without the drag of a contact seal, but is not liquid-tight — use 2RSH for wet or fine-dust positions.
• The 20.8/19.6 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.