61917-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 61917-RSR-NTN model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61917 carries bore code 17 = 85 mm. Outside diameter 120 mm and width 18 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 85 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6917LLB), 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 85 mm of 61917-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 619xx thin section (17.5 mm section height at 85 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
• RSR low-friction seals on 61917-RSR-NTN run faster than contact-seal 61917-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61917-2RS instead.
• The non-contact lip of 61917-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 85 mm bore position before relying on it as sealed-for-life.
• The housing bore for the 120 mm OD should be round within IT7; an oval bore pinches the outer ring of 61917-RSR-NTN and shows up later as two-point loaded raceway wear.
• Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 18 mm-wide ring of 61917-RSR-NTN drags the lip and overheats it.
• NTN catalogues this low-friction non-contact seal as 6917LLB (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 85 mm bore 61917 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.
• At 5400 r/min the grease limiting speed for 61917 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.
• NTN rates 61917 at 35.5 kN dynamic (C) and 29.6 kN static (C0), 1.99 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.
• At 536 g, 61917 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 85×120×18 mm envelope of 61917 gives a D/d ratio of 1.41 and 17.5 mm radial section height — this 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 35.5/29.6 kN load ratings, 1.99 kN fatigue load limit Cu NTN lists the grease limiting speed at 5400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 536 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6917LLB on the 85×120×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61917 in a rated drive.
• NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.
• 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 61917 is listed.