61809-RSR-NTN bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)) · extracted 2026-09-25

Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.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 61809-RSR-NTN model number is decoded

61809-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 09 by five gives the 45 mm bore; the 58 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 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. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6809JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it 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-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
• The 618xx thin section at 45 mm bore has only a 6.5 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 6209.
• RSR low-friction seals on 61809-RSR-NTN 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 non-contact lip of 61809-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 45 mm bore position before relying on it as sealed-for-life.
• A 45 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
• Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
• NTN catalogues this low-friction non-contact seal as 6809JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).
• The 45 mm bore puts 61809 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.
• At 11000 r/min the grease limiting speed for 61809 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.
• NTN rates 61809 at 5.95 kN dynamic (C) and 4.95 kN static (C0), 0.33 kN fatigue load limit Cu; 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 40 g, 61809 is a lightweight 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 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 5.95/4.95 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 40 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6809JRLLB 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.
• Order the C3 internal-clearance version (61809 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.
• NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61809 is listed.