61808-2RS 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 61808-2RS model number is decoded

61808-2RS 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 08 by five gives the 40 mm bore; the 52 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. SKF's contact-seal catalogue number is 61808-2RS1 (older text: -2RS1), mapped here from the industry-neutral -2RS spelling.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• A 40 mm shaft for 61808 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.
• Only 6.0 mm of radial section separates bore and OD on the 618xx series at 40 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6208.
• Contact seals add drag and heat: 61808-2RS runs slower and cooler-limited than the open 61808; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
• Heat is the enemy of the sealed 61808-2RS: 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.
• Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
• Suffixes stack in a defined order — clearance follows the seal code, e.g. 61808-C3. No clearance suffix means normal CN clearance.
• SKF catalogues the contact-sealed version as 61808-2RS1 (older printings may read -2RS1); it is shipped pre-greased and its 7500 r/min limiting speed is set by seal-lip drag and grease life versus the open bearing's 26000 r/min thermal reference speed.
• The 4.49/3.75 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.