61909-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 61909-RSR-NSK model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61909 carries bore code 09 = 45 mm. Outside diameter 68 mm and width 12 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 6909VV), 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

• Sizes around 45 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61909-RSR-NSK.
• The 619xx thin section (11.5 mm section height at 45 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
• The low-drag lip of 61909-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.
• The non-contact lip of 61909-RSR-NSK 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.
• Vibration during standstill brinells the raceways of a 45 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.
• The housing bore for the 68 mm OD should be round within IT7; an oval bore pinches the outer ring of 61909-RSR-NSK and shows up later as two-point loaded raceway wear.
• NSK catalogues this low-friction non-contact seal as 6909VV (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 61909 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.
• At 15.5 kN dynamic load rating (C) and 10.9 kN static (C0), 61909 is a medium-load NSK bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NSK catalogue.
• At 126 g, 61909 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.
• The 45×68×12 mm envelope of 61909 gives a D/d ratio of 1.51 and 11.5 mm radial section height — this NSK thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.
• The 15.5/10.9 kN load ratings, mass 126 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6909VV on the 45×68×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61909 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.
• NSK supplies its sealed units pre-greased for general duty between roughly -10 and +110 °C; low-temperature, food-grade and high-temperature fills are special executions — ask at order time, because DDU/VV units are not designed to be opened and repacked.