61809-RSR-NSK bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24

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 61809-RSR-NSK model number is decoded

In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61809 carries bore code 09 = 45 mm. Outside diameter 58 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NSK's non-contact seal suffix is VV (catalogue number 6809VV), mapped here from the industry-neutral -RSR spelling; speed capability is close to the open bearing but VV is not liquid-tight.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61809-RSR-NSK; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
• Only 6.5 mm of radial section separates bore and OD on the 618xx series at 45 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6209.
• RSR low-friction seals on 61809-RSR-NSK run faster than contact-seal 61809-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61809-2RS instead.
• The low-drag lip of 61809-RSR-NSK barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.
• 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.
• 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.
• NSK catalogues this low-friction non-contact seal as 6809VV (suffix VV), mapped here from the industry-neutral -RSR spelling. NSK rates its speed capability close to the open bearing, but VV is not liquid-tight — for wet or fine-dust duty step up to the DDU contact seal (industry-neutral -2RS).
• The 45 mm bore puts 61809 in NSK's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty. NSK's VV non-contact seal is the high-speed choice here — DDU contact seal costs roughly 30–40% of the open-bearing speed ceiling.
• NSK rates 61809 at 7.25 kN dynamic (C) and 6.15 kN static (C0); this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.
• At only 38 g, 61809 is a lightweight NSK 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 45×58×7 mm envelope of 61809 gives a D/d ratio of 1.29 and only 6.5 mm radial section height — this is an ultra-thin section in NSK's E1103 catalogue where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.
• The 7.25/6.15 kN load ratings, mass 38 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6809VV on the 45×58×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61809 in a rated drive. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
• Standard P0 runout from NSK is adequate up to the catalogue limiting speed on ground shaft seats; spindle or instrument positions should specify P6/P5 accuracy explicitly — it is a different order code, not a sorting of standard stock.
• Keep NSK bearings in the original packaging until fitting: the wrapper carries the production lot, and the unopened shelf life of greased sealed units is typically quoted at three to five years in dry, vibration-free storage.