61820-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 61820-RSR-NTN model number is decoded

61820-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 20 by five gives the 100 mm bore; the 125 mm outside diameter and 13 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 100 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 6820LLB), 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

• Large bores like the 100 mm of 61820-RSR-NTN 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 100 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 6220.
• The low-drag lip of 61820-RSR-NTN 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 61820-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 100 mm bore position before relying on it as sealed-for-life.
• Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 13 mm-wide ring of 61820-RSR-NTN drags the lip and overheats it.
• A 100 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.
• NTN catalogues this low-friction non-contact seal as 6820LLB (suffix LB), 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).
• At 100 mm bore 61820 is in NTN's medium industrial range; the pressed-steel cage is standard but large-section 63xx/64xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.
• NTN lists the grease limiting speed at 4800 r/min for 61820; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.
• At 21.7 kN dynamic load rating (C) and 21.2 kN static (C0), 1.33 kN fatigue load limit Cu, 61820 is a medium-load 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 NTN catalogue.
• At 313 g, 61820 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.
• The 100×125×13 mm envelope of 61820 gives a D/d ratio of 1.25 and only 12.5 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 21.7/21.2 kN load ratings, 1.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 4800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 313 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6820LLB on the 100×125×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61820 in a rated drive.
• Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.
• 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 61820 is listed.